0001680062-24-000008 | 10-K | XBRL Viewer

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ACCOUNTS RECEIVABLE - Summary of Accounts Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Receivables [Abstract]
Accounts receivable	$ 288,016	$ 182,936
Less: Allowance for credit losses	(4,830)	0
Accounts receivable	$ 283,186	$ 182,936

STOCK-BASED COMPENSATION, Share Option Activities (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	May 31, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Employee stock option plan
Number of Option Share [Roll Forward]
Outstanding, beginning of period (in shares)		9,211,641	8,402,247	9,574,233
Granted (in shares)		2,230,500	1,653,300	421,200
Exercised (in shares)		(1,080,952)	(416,546)	(1,431,174)
Forfeited/cancelled (in shares)		(362,552)	(427,360)	(162,012)
Outstanding, end of period (in shares)		9,998,637	9,211,641	8,402,247	9,574,233
Vested and exercisable (in shares)		6,044,572
Weighted Average Grant Date Fair Value [Abstract]
Outstanding at beginning of period (in dollars per share)		$ 3.58	$ 2.45	$ 1.71
Granted (in dollars per share)		10.38	10.31	16.05
Exercised (in dollars per share)		0.90	1.20	0.82
Forfeited/cancelled (in dollars per share)		11.24	11.41	8.32
Outstanding at end of period (in dollars per share)		5.15	3.58	2.45	$ 1.71
Weighted Average Exercise Price [Abstract]
Outstanding, beginning of period (in dollars per share)		8.24	5.88	4.24
Granted (in dollars per share)		13.91	22.41	35.38
Exercised (in dollars per share)		2.28	2.97	2.10
Forfeited/cancelled (in dollars per share)		22.92	25.24	19.03
Outstanding, end of period (in dollars per share)		$ 9.47	$ 8.24	$ 5.88	$ 4.24
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Additional Disclosures [Abstract]
Weighted Average Remaining Contractual Term		6 years 2 months 1 day	6 years 4 months 9 days	6 years 6 months 10 days	7 years 1 month 17 days
Unrecognized employee stock-based compensation expense		$ 27,152
Cost not yet recognized		3 years 11 months 15 days
Intrinsic value		$ 15,457	$ 6,429	$ 43,356
Outstanding intrinsic value		108,771
Intrinsic value, exercisable		$ 82,848
Employee stock option plan \| ACM Research (Shanghai), Inc.
Number of Option Share [Roll Forward]
Exercised (in shares)	(2,150,309)
Employee stock option plan \| ACM Research (Shanghai), Inc. \| 2019 Stock Option Incentive Plan
Number of Option Share [Roll Forward]
Outstanding, beginning of period (in shares)		5,377,500	5,377,500	5,423,654
Exercised (in shares)		(2,150,309)
Forfeited/cancelled (in shares)		(92,308)		(46,154)
Outstanding, end of period (in shares)		3,134,883	5,377,500	5,377,500	5,423,654
Vested and exercisable (in shares)		492,308
Weighted Average Grant Date Fair Value [Abstract]
Outstanding at beginning of period (in dollars per share)		$ 0.23	$ 0.24
Exercised (in dollars per share)		0.20
Forfeited/cancelled (in dollars per share)		0.22		$ 0.24
Outstanding at end of period (in dollars per share)		0.24	0.23	0.24
Weighted Average Exercise Price [Abstract]
Outstanding, beginning of period (in dollars per share)		1.93	2.04
Exercised (in dollars per share)		1.85
Forfeited/cancelled (in dollars per share)		1.85		2.04
Outstanding, end of period (in dollars per share)		$ 1.85	$ 1.93	$ 2.04
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Additional Disclosures [Abstract]
Weighted Average Remaining Contractual Term		10 months 6 days	1 year 9 months 3 days	2 years 6 months
Intrinsic value		$ 31,144	$ 0	$ 0
Outstanding intrinsic value		40,663
Intrinsic value, exercisable		$ 6,386
Employee stock option plan \| ACM Research (Shanghai), Inc. \| 2023 Stock Option Incentive Plan
Number of Option Share [Roll Forward]
Outstanding, beginning of period (in shares)		0
Granted (in shares)		10,648,500
Forfeited/cancelled (in shares)		(73,000)
Outstanding, end of period (in shares)		10,575,500	0
Vested and exercisable (in shares)		0
Weighted Average Grant Date Fair Value [Abstract]
Outstanding at beginning of period (in dollars per share)		$ 0
Granted (in dollars per share)		9.49
Forfeited/cancelled (in dollars per share)		9.49
Outstanding at end of period (in dollars per share)		9.49	$ 0
Weighted Average Exercise Price [Abstract]
Outstanding, beginning of period (in dollars per share)		0
Granted (in dollars per share)		7.06
Forfeited/cancelled (in dollars per share)		7.06
Outstanding, end of period (in dollars per share)		$ 7.06	$ 0
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Additional Disclosures [Abstract]
Weighted Average Remaining Contractual Term		3 years 1 month 2 days	0 years
Outstanding intrinsic value		$ 81,981
Non-employee stock option plan
Number of Option Share [Roll Forward]
Outstanding, beginning of period (in shares)		1,483,658	2,067,018	2,508,114
Exercised (in shares)		(299,934)	(563,808)	(439,629)
Forfeited/cancelled (in shares)		(12,929)	(19,552)	(1,467)
Outstanding, end of period (in shares)		1,170,795	1,483,658	2,067,018	2,508,114
Vested and exercisable (in shares)		1,167,045
Weighted Average Grant Date Fair Value [Abstract]
Outstanding at beginning of period (in dollars per share)		$ 0.38	$ 0.33	$ 0.34
Exercised (in dollars per share)		0.24	0.21	0.37
Forfeited/cancelled (in dollars per share)		0.22	0.21	0.11
Outstanding at end of period (in dollars per share)		0.42	0.38	0.33	$ 0.34
Weighted Average Exercise Price [Abstract]
Outstanding, beginning of period (in dollars per share)		1.15	0.97	1.02
Exercised (in dollars per share)		0.55	0.51	1.28
Forfeited/cancelled (in dollars per share)		0.50	0.48	0.28
Outstanding, end of period (in dollars per share)		$ 1.31	$ 1.15	$ 0.97	$ 1.02
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Additional Disclosures [Abstract]
Weighted Average Remaining Contractual Term		2 years 7 months 28 days	3 years 8 months 4 days	3 years 11 months 23 days	4 years 11 months 1 day
Unrecognized employee stock-based compensation expense		$ 9
Cost not yet recognized		2 months 12 days
Intrinsic value		$ 3,796	$ 9,110	$ 11,993
Outstanding intrinsic value		21,342
Intrinsic value, exercisable		21,301
Non-employee stock option plan \| ACM Research (Shanghai), Inc.
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Additional Disclosures [Abstract]
Unrecognized employee stock-based compensation expense		$ 79,882
Cost not yet recognized		2 years 1 month 6 days

SEGMENT INFORMATION (Tables)

12 Months Ended

Dec. 31, 2023

Segment Reporting [Abstract]

Long-Lived Assets by Geographic Region

Long-lived assets by geographic region as of the years ended were as follows:


	December 31,
	2023		2022
Long-lived assets by geography:
Mainland China	$	209,725	$	140,481
Korea	12,190		3,830
United States	1,276		10
Total	$	223,191	$	144,321

REVENUE FROM CONTRACTS WITH CUSTOMERS

12 Months Ended

Dec. 31, 2023

Revenue from Contract with Customer [Abstract]

REVENUE FROM CONTRACTS WITH CUSTOMERS

The Company assesses revenues based upon the nature or type of goods or services it provides and the geographic location of the customer facility. The following tables present disaggregated revenue information:


	Year Ended December 31,
	2023		2022		2021
Single Wafer Cleaning, Tahoe and Semi-Critical Cleaning Equipment	$	403,851	$	272,939	$	189,208
ECP (front-end and packaging), Furnace and Other Technologies	103,356		77,482		33,210
Advanced Packaging (excluding ECP), Services & Spares	50,516		38,411		37,333
Total Revenue By Product Category	$	557,723	$	388,832	$	259,751


	Year Ended December 31,
	2023		2022		2021
Mainland China	$	540,969	$	377,752	$	258,615
Other regions	16,754		11,080		1,136
	$	557,723	$	388,832	$	259,751

Below are the accounts receivables and contract liabilities balances as of:


	December 31, 2023		December 31, 2022

Accounts receivable	$	283,186	$	182,936
Advances from customers	181,368		153,773
Deferred revenue	3,687		4,174

During the year ended December 31, 2023, advances from customers increased by $27,595 primarily due to a net increase of payments made by customers for first tools under evaluation.

Below are revenues recognized from amounts included in contract liabilities at the beginning of the year:


	Year Ended December 31,
	2023		2022		2021
Revenue recognized from amounts included in contract liabilities at the beginning of the year	$	97,370	$	30,385	$	13,425

- Definition

The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-9

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-10

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-15

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-12

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-12

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-12

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-12

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-12

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-13

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Name Accounting Standards Codification
-Topic 606
-Publisher FASB
-URI https://asc.fasb.org//606/tableOfContent

+ Details

SHORT-TERM INVESTMENTS (Tables)

12 Months Ended

Dec. 31, 2023

Investments, Debt and Equity Securities [Abstract]

Components of Short-Term Investments

The components of short-term investments were as follows:


	December 31,
	2023		2022
Short-term investments listed in Shanghai Stock Exchange
Cost	$	20,155	$	14,779
Market value	$	21,312	$	20,209

STOCK-BASED COMPENSATION, Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Stock-based Compensation Expense [Abstract]
Share-based compensation expense	$ 27,338	$ 7,730	$ 5,117
Employee stock option plan
Stock-based Compensation Expense [Abstract]
Share-based compensation expense	6,213	7,346	4,674
Employee stock option plan \| ACM Research (Shanghai), Inc.
Stock-based Compensation Expense [Abstract]
Share-based compensation expense	21,079	338	349
Non-employee stock option plan
Stock-based Compensation Expense [Abstract]
Share-based compensation expense	46	46	94
Cost of revenue
Stock-based Compensation Expense [Abstract]
Share-based compensation expense	1,406	520	397
Sales and marketing expense
Stock-based Compensation Expense [Abstract]
Share-based compensation expense	5,684	1,877	1,802
Research and development expense
Stock-based Compensation Expense [Abstract]
Share-based compensation expense	8,459	2,565	1,115
General and administrative expense
Stock-based Compensation Expense [Abstract]
Share-based compensation expense	$ 11,789	$ 2,768	$ 1,803

OTHER LONG-TERM LIABILITIES (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Other Long-term Liabilities [Abstract]
Other long-term liabilities	$ 5,873	$ 7,321
Subsidies to Stress Free Polishing project, commenced in 2008 and 2017
Other Long-term Liabilities [Abstract]
Other long-term liabilities	475	611
Subsidies to other cleaning tools, commenced in 2020
Other Long-term Liabilities [Abstract]
Other long-term liabilities	632	785
Subsidies to SW Lingang R&D development in 2021
Other Long-term Liabilities [Abstract]
Other long-term liabilities	3,467	4,266
Subsidies to CO2 Technology
Other Long-term Liabilities [Abstract]
Other long-term liabilities	275	965
Other
Other Long-term Liabilities [Abstract]
Other long-term liabilities	$ 1,024	$ 694

STOCK-BASED COMPENSATION (Tables)

12 Months Ended

Dec. 31, 2023

Share-Based Payment Arrangement [Abstract]

Summary of Share Option Activities

The following table summarizes the ACM’s employee share option activities during the years ended December 31, 2021, 2022 and 2023:


	Number of Option Shares	Weighted Average Grant Date Fair Value		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term
Outstanding at December 31, 2020	9,574,233	$	1.71	$	4.24	7.13 years
Granted	421,200	16.05		35.38
Exercised	(1,431,174)	0.82		2.10
Forfeited/cancelled	(162,012)	8.32		19.03
Outstanding at December 31, 2021	8,402,247	$	2.45	$	5.88	6.53 years
Granted	1,653,300	10.31		22.41
Exercised	(416,546)	1.20		2.97
Forfeited/cancelled	(427,360)	11.41		25.24
Outstanding at December 31, 2022	9,211,641	$	3.58	$	8.24	6.36 years
Granted	2,230,500	10.38		13.91
Exercised	(1,080,952)	0.90		2.28
Forfeited/cancelled	(362,552)	11.24		22.92
Outstanding at December 31, 2023	9,998,637	$	5.15	$	9.47	6.17 years
Vested and exercisable at December 31, 2023	6,044,572

The following table summarizes the ACM's non-employee share option activities during the years ended December 31, 2021, 2022 and 2023:


	Number of Option Shares (1)	Weighted Average Grant Date Fair Value (1)		Weighted Average Exercise Price (1)		Weighted Average Remaining Contractual Term
Outstanding at December 31, 2020	2,508,114	$	0.34	$	1.02	4.92 years
Exercised	(439,629)	0.37		1.28
Forfeited/cancelled	(1,467)	0.11		0.28
Outstanding at December 31, 2021	2,067,018	$	0.33	$	0.97	3.98 years
Exercised	(563,808)	0.21		0.51
Forfeited/cancelled	(19,552)	0.21		0.48
Outstanding at December 31, 2022	1,483,658	$	0.38	$	1.15	3.68 years
Exercised	(299,934)	0.24		0.55
Forfeited/cancelled	(12,929)	0.22		0.50
Outstanding at December 31, 2023	1,170,795	$	0.42	$	1.31	2.66 years
Vested and exercisable at December 31, 2023	1,167,045

The following table summarizes the ACM Shanghai employee stock option activities during the years ended December 31, 2023, 2022 and 2021 :


	Number of Option Shares in ACM Shanghai	Weighted Average Grant Date Fair Value		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term
Outstanding at December 31, 2020	5,423,654
Forfeited/cancelled	(46,154)	0.24		2.04		2.50 years
Outstanding at December 31, 2021	5,377,500	$	0.24	$	2.04	2.50 years
Outstanding at December 31, 2022	5,377,500	$	0.23	$	1.93	1.76 years
Exercised	(2,150,309)	0.20		1.85
Forfeited/cancelled	(92,308)	0.22		1.85
Outstanding at December 31, 2023	3,134,883	$	0.24	$	1.85	0.85 years
Vested and exercisable at December 31, 2023	492,308

The aggregate intrinsic value of options exercised in the years ended December 31, 2023 and 2022 and 2021 was $31,144, nil and nil, respectively. The aggregate intrinsic value of options outstanding and exercisable as of December 31, 2023 were $40,663 and $6,386, respectively.

The following table summarizes the ACM Shanghai 2023 Subsidiary Stock Option Plan’s stock option activities during the year ended December 31, 2023:


	Number of Option Shares in ACM Shanghai	Weighted Average Grant Date Fair Value		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term
Outstanding at December 31, 2022	—	$	—	$	—	0.00 years
Granted	10,648,500	$	9.49	$	7.06
Forfeited/cancelled	(73,000)	$	9.49	$	7.06	3.09 years
Outstanding at December 31, 2023	10,575,500	$	9.49	$	7.06	3.09 years
Vested and exercisable at December 31, 2023	—

Assumptions Used to Determine Fair Value of Options Granted

The fair value of options granted to employees is estimated on the grant date using the Black-Scholes valuation model with the following assumptions:


	Year ended December 31,
	2023		2022		2021
Fair value of common stock(1)	$11.85-$17.23		$16.83- 25.45		$12.79- 17.02
Expected term in years(2)	5.50-6.25		5.50-6.25		6.25
Volatility(3)	84.95-86.45%		49.43-50.87%		48.53-49.47%
Risk-free interest rate(4)	4.16%-4.69%		1.70%-3.04%		1.00%-1.44%
Expected dividend(5)	0	%	0	%	0	%

(1)Fair value of Class A common stock value was the closing market price of the Class A common stock on the grant date.

(2)Expected term of share options is based on the average of the vesting period and the contractual term for each grant.

(3)Volatility is calculated based on the historical volatility of ACM in the period equal to the expected term of each grant.

(4)Risk-free interest rate is based on the yields of U.S. Treasury securities with maturities similar to the expected term of the share options in effect at the time of grant.

(5)Expected dividend is assumed to be 0% as ACM has no history or expectation of paying a dividend on its common stock.

The fair value of options granted to employees is estimated on the grant date using the Black-Scholes valuation with following assumptions:


			Year Ended December 31, 2023
Fair value of share of common stock (1)			$14.87
Expected term in years (2)			1.5-4.5
Volatility (3)			60.00%-60.60%
Risk-free interest rate (4)			1.50%-2.75%

(1) Equal to closing value on the grant date.

(2) Expected term of share options is based on the average of the vesting period and the contractual term for each grant.

(3) Volatility is calculated based on the historical volatility of ACM in the period equal to the expected term of each grant.

(4) Risk-free interest rate is based on the yields of RMB deposit in mainland China with maturities similar to the expected term of the share options in effect at the time of grant.

The aggregate intrinsic value of options outstanding as of December 31, 2023 was $81,981.

Components of Stock-based Compensation Expense

The following table summarizes the components of stock-based compensation expense included in the consolidated statements of comprehensive income (loss):


	Year Ended December 31,
	2023		2022		2021
Stock-Based Compensation Expense:
Cost of revenue	$	1,406	$	520	$	397
Sales and marketing expense	5,684		1,877		1,802
Research and development expense	8,459		2,565		1,115
General and administrative expense	11,789		2,768		1,803
	$	27,338	$	7,730	$	5,117


	Year Ended December 31,
	2023		2022		2021
Stock-based compensation expense by type:
Employee stock option plan	$	6,213	$	7,346	$	4,674
Non-employee stock option plan	46		46		94
2019 and 2023 Subsidiary stock option plans	21,079		338		349
	$	27,338	$	7,730	$	5,117

LEASES - Maturities of Operating Leases Outstanding Liabilities (Details) $ in Thousands	Dec. 31, 2023 USD ($)
Leases [Abstract]
2024	$ 3,016
2025	1,767
2026	1,207
2027	1,150
2028 and thereafter	595
Total lease payments	7,735
Less: Interest	(709)
Present value of lease liabilities	$ 7,026

SHORT-TERM INVESTMENTS - Summary of Short-term Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Cost	$ 20,155	$ 14,779
Market value	$ 21,312	$ 20,209

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Operating and Financial Risks (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) customer	Dec. 31, 2022 USD ($) customer	Dec. 31, 2021 USD ($) customer
Foreign Currency Risk and Translation [Abstract]
Foreign currency translation adjustment, net of tax \| $	$ (10,617)	$ (59,102)	$ 4,695
Two Customers \| Revenue Benchmark \| Customer Concentration Risk
Concentration of Credit Risk [Abstract]
Number of major customers	4	2
Two Customers \| Accounts Receivable \| Customer Concentration Risk
Concentration of Credit Risk [Abstract]
Concentration risk percentage	59.10%	42.60%
Three Customers \| Revenue Benchmark \| Customer Concentration Risk
Concentration of Credit Risk [Abstract]
Number of major customers	3	3	2
Concentration risk percentage	45.50%	43.80%	48.90%

RELATED PARTY BALANCES AND TRANSACTIONS

12 Months Ended

Dec. 31, 2023

RELATED PARTY BALANCES AND TRANSACTIONS

Ninebell

Ninebell is an equity investee of ACM (Note 14) and is the Company’s principal supplier of robotic delivery system subassemblies used in our single-wafer cleaning equipment. The Company purchases equipment from Ninebell for production in the ordinary course of business. The Company pays for a portion of the equipment in advance and is obligated for the remaining amounts upon receipt of the product.

Shengyi

Shengyi is an equity investee of ACM Shanghai (Note 14) and is one of the Company’s component suppliers in mainland China. The Company purchases components from Shengyi for production in the ordinary course of business. The Company incurs a service fee related to installation and hook-up fees which is recorded within cost of revenue on the Company’s consolidated statements of comprehensive income (loss). The Company pays for a portion of the raw materials in advance and is obligated for the remaining amounts upon receipt of the product.

All related party outstanding balances are short-term in nature and are expected to be settled in cash.

The following tables represent related party transactions with the equity investees as of December 31, 2023 and 2022:


	December 31,
Advances to related party	2023		2022
Ninebell	$	2,432	$	3,322


	December 31,
Accounts payable	2023		2022
Ninebell	$	7,624	$	10,526
Shengyi	3,783		3,942
Total	$	11,407	$	14,468


	Year Ended December 31
Purchase of materials	2023		2022		2021
Ninebell	$	42,737	$	40,985	$	33,659
Shengyi	5,006		5,350		2,434
Total	$	47,743	$	46,335	$	36,093


	Year Ended December 31
Service fee charged by	2023		2022		2021
Shengyi	$	820	$	543	$	561
Total	$	820	$	543	$	561

- Definition

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-5

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-Publisher FASB
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
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-Name Accounting Standards Codification
-Section S99
-Paragraph 1
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-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

+ Details

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Property, Plant and Equipment, Net (Details)	Dec. 31, 2023
Buildings and plants
Property, Plant and Equipment, Net [Abstract]
Estimated useful lives	30 years
Furniture and fixtures
Property, Plant and Equipment, Net [Abstract]
Estimated useful lives	5 years
Minimum \| Computer and office equipment
Property, Plant and Equipment, Net [Abstract]
Estimated useful lives	3 years
Minimum \| Electronic equipment
Property, Plant and Equipment, Net [Abstract]
Estimated useful lives	3 years
Minimum \| Manufacturing equipment
Property, Plant and Equipment, Net [Abstract]
Estimated useful lives	5 years
Minimum \| Transportation equipment
Property, Plant and Equipment, Net [Abstract]
Estimated useful lives	4 years
Maximum \| Computer and office equipment
Property, Plant and Equipment, Net [Abstract]
Estimated useful lives	5 years
Maximum \| Electronic equipment
Property, Plant and Equipment, Net [Abstract]
Estimated useful lives	5 years
Maximum \| Manufacturing equipment
Property, Plant and Equipment, Net [Abstract]
Estimated useful lives	10 years
Maximum \| Transportation equipment
Property, Plant and Equipment, Net [Abstract]
Estimated useful lives	5 years

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Recurring
Financial Liabilities Fair Value Disclosure [Abstract]
Cash and cash equivalents	$ 182,090	$ 247,951
Short-term investments	21,312	20,209
Assets	203,402	268,160
Fair Value, Recurring \| Quoted Prices in Active Markets for Identical Liabilities (Level 1)
Financial Liabilities Fair Value Disclosure [Abstract]
Cash and cash equivalents	182,090	247,951
Short-term investments	21,312	20,209
Assets	203,402	268,160
Fair Value, Recurring \| Significant Other Observable Inputs (Level 2)
Financial Liabilities Fair Value Disclosure [Abstract]
Cash and cash equivalents	0	0
Short-term investments	0	0
Assets	0	0
Fair Value, Recurring \| Significant Unobservable Inputs (Level 3)
Financial Liabilities Fair Value Disclosure [Abstract]
Cash and cash equivalents	0	0
Short-term investments	0	0
Assets	0	$ 0
Fair Value, Nonrecurring
Financial Liabilities Fair Value Disclosure [Abstract]
Investments accounted for using measurement alternative	10,378
Assets	10,378
Fair Value, Nonrecurring \| Quoted Prices in Active Markets for Identical Liabilities (Level 1)
Financial Liabilities Fair Value Disclosure [Abstract]
Investments accounted for using measurement alternative	0
Assets	0
Fair Value, Nonrecurring \| Significant Other Observable Inputs (Level 2)
Financial Liabilities Fair Value Disclosure [Abstract]
Investments accounted for using measurement alternative	0
Assets	0
Fair Value, Nonrecurring \| Significant Unobservable Inputs (Level 3)
Financial Liabilities Fair Value Disclosure [Abstract]
Investments accounted for using measurement alternative	10,378
Assets	$ 10,378

SHORT-TERM INVESTMENTS - Additional Information (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Jul. 31, 2023	Dec. 31, 2022	Sep. 27, 2022	Sep. 19, 2022
Nuode Asset Fund
Debt and Equity Securities, FV-NI [Line Items]
Investment in partnership				$ 4,196	$ 22,160
Ownership percentage in partnership			18.75%	18.75%
Huahong Semiconductor Limited
Debt and Equity Securities, FV-NI [Line Items]
Investment in partnership		$ 13,930
Zhongiuxin Limited Company
Debt and Equity Securities, FV-NI [Line Items]
Investment in partnership	$ 4,179

DESCRIPTION OF BUSINESS - Additional Information (Details) $ in Thousands	1 Months Ended			12 Months Ended
	May 31, 2023 shares	Mar. 31, 2022	Nov. 30, 2021 USD ($) shares	Dec. 31, 2023 shares	Dec. 31, 2022 shares	Dec. 31, 2021 shares	Dec. 31, 2020 USD ($)	Mar. 16, 2022 shares	Nov. 30, 2021 ¥ / shares shares	Nov. 08, 2017	Aug. 31, 2017
Description of Business [Abstract]
Stock split ratio		3
Employee stock option plan
Description of Business [Abstract]
Exercise of stock options (in shares)				1,080,952	416,546	1,431,174
Class A Common Stock
Description of Business [Abstract]
Common Stock, Shares, Outstanding				56,036,172	54,655,286
Stock split ratio		3
Additional shares reserved for issuance as dividends (in shares)								2
Class B Common Stock
Description of Business [Abstract]
Common Stock, Shares, Outstanding				5,021,811	5,021,811
Additional shares reserved for issuance as dividends (in shares)								2
ACM Research (Shanghai), Inc.
Description of Business [Abstract]
Purchase of equity interest percentage				8.30%						18.36%	18.77%
Term to complete listing of shares				3 years
Percentage of shares owned by company after stock issuance	82.10%
ACM Research (Shanghai), Inc. \| Employee stock option plan
Description of Business [Abstract]
Exercise of stock options (in shares)	2,150,309
ACM Research (Shanghai), Inc. \| IPO
Description of Business [Abstract]
Offering of shares (in shares)			43,355,753
Percentage amount of shares offered from shares outstanding									10.00%
Common Stock, Shares, Outstanding									433,557,100
Sale of stock (in RMD per share) \| ¥ / shares									¥ 85.00
Net proceeds of stock issuance cost \| $			$ 545,512
Percentage of shares owned by company after stock issuance			82.50%
ACM Research (Lingang), Inc. (1)
Description of Business [Abstract]
Purchase of equity interest percentage				91.70%
CleanChip Technologies Limited
Description of Business [Abstract]
Proceeds from divestiture of interest in consolidated subsidiaries \| $							$ 3,500

Audit Information	12 Months Ended
Audit Information	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Audit Information [Abstract]
Auditor Name	Ernst & Young Hua Ming LLP	Armanino LLP	BDO China Shu Lun Pan Certified Public Accountants LLP
Auditor Location	Shanghai, China	San Ramon, CA	Shenzhen, China
Auditor Firm ID	1408	32	1818

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Shipping and Handling Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Shipping and Handling Costs [Abstract]
Sales and marketing expenses	$ 47,019	$ 39,889	$ 26,733
Shipping and Handling
Shipping and Handling Costs [Abstract]
Sales and marketing expenses	$ 1,582	$ 1,507	$ 923

LAND USE RIGHT, NET (Tables)

12 Months Ended

Dec. 31, 2023

LAND USE RIGHT, NET [Abstract]

Land Use Rights

A summary of land use right is as follows:


	December 31,
	2023		2022
Land use right purchase amount	$	8,996	$	9,149
Less: accumulated amortization	(629)		(457)
Land use right, net	$	8,367	$	8,692

Annual Amortization of Land Use Right

The annual amortization of land use right for each of the five succeeding years is as follows:


Year ending December 31,
2024	$	180
2025	180
2026	180
2027	180
2028	180
2029 and thereafter	7,467
Total	$	8,367

LEASES - Components of Lease Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Operating lease cost	$ 3,580	$ 2,816	$ 2,451
Short-term lease cost	923	786	394
Lease cost	$ 4,503	$ 3,602	$ 2,845

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Cash and Cash Equivalents (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2023 CNY (¥)	Dec. 31, 2022 USD ($)
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash, cash equivalents and restricted cash and time deposits	$ 182,090		$ 247,951
Short-term and long-term time deposits	121,342		172,448
ACM Shanghai
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash payments for procurement of goods and services	42,500		30,200
Payments of Ordinary Dividends, Common Stock \| ¥		¥ 19,200
United States
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash, cash equivalents and restricted cash and time deposits	43,614		25,011
Mainland China
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash, cash equivalents and restricted cash and time deposits	70,418		129,695
China Hong Kong
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash, cash equivalents and restricted cash and time deposits	64,057		89,187
Korea
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash, cash equivalents and restricted cash and time deposits	3,934		4,007
Singapore
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash, cash equivalents and restricted cash and time deposits	$ 67		$ 51

REVENUE FROM CONTRACTS WITH CUSTOMERS (Tables)

12 Months Ended

Dec. 31, 2023

Revenue from Contract with Customer [Abstract]

Disaggregated Revenue Information


	Year Ended December 31,
	2023		2022		2021
Single Wafer Cleaning, Tahoe and Semi-Critical Cleaning Equipment	$	403,851	$	272,939	$	189,208
ECP (front-end and packaging), Furnace and Other Technologies	103,356		77,482		33,210
Advanced Packaging (excluding ECP), Services & Spares	50,516		38,411		37,333
Total Revenue By Product Category	$	557,723	$	388,832	$	259,751


	Year Ended December 31,
	2023		2022		2021
Mainland China	$	540,969	$	377,752	$	258,615
Other regions	16,754		11,080		1,136
	$	557,723	$	388,832	$	259,751

Accounts Receivables and Contract Liabilities

Below are the accounts receivables and contract liabilities balances as of:


	December 31, 2023		December 31, 2022

Accounts receivable	$	283,186	$	182,936
Advances from customers	181,368		153,773
Deferred revenue	3,687		4,174

Below are revenues recognized from amounts included in contract liabilities at the beginning of the year:


	Year Ended December 31,
	2023		2022		2021
Revenue recognized from amounts included in contract liabilities at the beginning of the year	$	97,370	$	30,385	$	13,425

RELATED PARTY BALANCES AND TRANSACTIONS (Tables)

12 Months Ended

Dec. 31, 2023

Related Party Balances and Transactions

The following tables represent related party transactions with the equity investees as of December 31, 2023 and 2022:


	December 31,
Advances to related party	2023		2022
Ninebell	$	2,432	$	3,322


	December 31,
Accounts payable	2023		2022
Ninebell	$	7,624	$	10,526
Shengyi	3,783		3,942
Total	$	11,407	$	14,468


	Year Ended December 31
Purchase of materials	2023		2022		2021
Ninebell	$	42,737	$	40,985	$	33,659
Shengyi	5,006		5,350		2,434
Total	$	47,743	$	46,335	$	36,093


	Year Ended December 31
Service fee charged by	2023		2022		2021
Shengyi	$	820	$	543	$	561
Total	$	820	$	543	$	561

Consolidated Statement of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Revision of Prior Period, Accounting Standards Update, Adjustment	Common Stock Class A	Common Stock Class B	Common Stock Common Stock Class A	Common Stock Common Stock Class B	Additional Paid- in Capital	Retained Earnings	Retained Earnings Revision of Prior Period, Accounting Standards Update, Adjustment	Statutory Surplus Reserve	Accumulated Other Comprehensive Income (Loss)	Non-controlling Interests
Beginning balance (in shares) at Dec. 31, 2020					50,690,079	5,407,818
Beginning balance at Dec. 31, 2020	$ 208,170				$ 5	$ 1	$ 102,000	$ 29,899		$ 4,388	$ 4,857	$ 67,020
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	42,921							37,757				5,164
Appropriation to statutory surplus reserves	0							(3,924)		3,924
Foreign currency translation adjustment	4,695										4,252	443
Exercise of stock options (in shares)					1,870,803
Exercise of stock options	3,430						3,430
Stock-based compensation	5,117						5,117
Exercise of warrants (in shares)					728,043
Exercise of stock warrants	1,820						1,820
Conversion of class B common shares to Class A common shares (in shares)					320,004	(320,004)
Proceeds from a subsidiary equity issuance	545,512						482,678					62,834
Ending balance (in shares) at Dec. 31, 2021					53,608,929	5,087,814
Ending balance at Dec. 31, 2021	811,665				$ 5	$ 1	595,045	63,732		8,312	9,109	135,461
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	50,564							39,263				11,301
Appropriation to statutory surplus reserves	0							(8,569)		8,569
Foreign currency translation adjustment	(59,102)										(49,655)	(9,447)
Exercise of stock options (in shares)					980,354
Exercise of stock options	1,314						1,314
Stock-based compensation	7,730						7,730
Conversion of class B common shares to Class A common shares (in shares)					66,003	(66,003)
Ending balance (in shares) at Dec. 31, 2022			54,655,286	5,021,811	54,655,286	5,021,811
Ending balance at Dec. 31, 2022	812,171	$ (1,769)			$ 5	$ 1	604,089	94,426	$ (1,769)	16,881	(40,546)	137,315
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	96,852							77,349				19,503
Appropriation to statutory surplus reserves								(13,179)		13,179
Foreign currency translation adjustment	(10,617)										(8,803)	(1,814)
Exercise of stock options (in shares)					1,380,886
Exercise of stock options	6,138				$ 1		2,303					3,834
Stock-based compensation	27,338						23,453					3,885
ACM Shanghai dividends	(3,951)											(3,951)
Ending balance (in shares) at Dec. 31, 2023			56,036,172	5,021,811	56,036,172	5,021,811
Ending balance at Dec. 31, 2023	$ 926,162				$ 6	$ 1	$ 629,845	$ 156,827		$ 30,060	$ (49,349)	$ 158,772

OTHER LONG-TERM LIABILITIES (Tables)

12 Months Ended

Dec. 31, 2023

Other Liabilities Disclosure [Abstract]

Other Long-Term Liabilities

Other long-term liabilities represent government subsidies received from mainland China governmental authorities for development and commercialization of certain technology but not yet recognized (note 2). As of December 31, 2023 and 2022, other long-term liabilities consisted of the following unearned government subsidies:


	December 31,
	2023		2022
Subsidies to Stress Free Polishing project, commenced in 2008 and 2017	$	475	$	611
Subsidies to other cleaning tools, commenced in 2020	632		785
Subsidies to SW Lingang R&D development in 2021	3,467		4,266
Subsidies to CO2 Technology	275		965
Other	1,024		694
Total	$	5,873	$	7,321

STOCK-BASED COMPENSATION

12 Months Ended

Dec. 31, 2023

Share-Based Payment Arrangement [Abstract]

STOCK-BASED COMPENSATION

ACM’s stock-based compensation consists of employee and non-employee awards issued under its 1998 Stock Option Plan and its 2016 Omnibus Incentive Plan. The vesting condition may consist of service period condition or certain performance conditions, as determined by the Board of Directors. The fair value of the stock options granted with a service period based condition and/or performance condition is estimated at the date of grant using the Black-Scholes option pricing model. The fair value of the stock options granted with a market based condition is estimated at the date of grant using the Monte Carlo simulation model.

Employee Awards

The following table summarizes the ACM’s employee share option activities during the years ended December 31, 2021, 2022 and 2023:


	Number of Option Shares	Weighted Average Grant Date Fair Value		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term
Outstanding at December 31, 2020	9,574,233	$	1.71	$	4.24	7.13 years
Granted	421,200	16.05		35.38
Exercised	(1,431,174)	0.82		2.10
Forfeited/cancelled	(162,012)	8.32		19.03
Outstanding at December 31, 2021	8,402,247	$	2.45	$	5.88	6.53 years
Granted	1,653,300	10.31		22.41
Exercised	(416,546)	1.20		2.97
Forfeited/cancelled	(427,360)	11.41		25.24
Outstanding at December 31, 2022	9,211,641	$	3.58	$	8.24	6.36 years
Granted	2,230,500	10.38		13.91
Exercised	(1,080,952)	0.90		2.28
Forfeited/cancelled	(362,552)	11.24		22.92
Outstanding at December 31, 2023	9,998,637	$	5.15	$	9.47	6.17 years
Vested and exercisable at December 31, 2023	6,044,572

As of December 31, 2023, $27,152 of total unrecognized employee stock-based compensation expense, net of estimated forfeitures, related to stock-based awards for ACM was expected to be recognized over a weighted-average period of 3.96 years. Total recognized compensation cost may be adjusted for future changes in estimated forfeitures.

The aggregate intrinsic value of options exercised in the years ended December 31, 2023, 2022, and 2021 was $15,457, $6,429, and $43,356, respectively. The aggregate intrinsic value of options outstanding and exercisable as of December 31, 2023 were $108,771 and $82,848, respectively.

The fair value of options granted to employees is estimated on the grant date using the Black-Scholes valuation model with the following assumptions:


	Year ended December 31,
	2023		2022		2021
Fair value of common stock(1)	$11.85-$17.23		$16.83- 25.45		$12.79- 17.02
Expected term in years(2)	5.50-6.25		5.50-6.25		6.25
Volatility(3)	84.95-86.45%		49.43-50.87%		48.53-49.47%
Risk-free interest rate(4)	4.16%-4.69%		1.70%-3.04%		1.00%-1.44%
Expected dividend(5)	0	%	0	%	0	%

(1)Fair value of Class A common stock value was the closing market price of the Class A common stock on the grant date.

(2)Expected term of share options is based on the average of the vesting period and the contractual term for each grant.

(3)Volatility is calculated based on the historical volatility of ACM in the period equal to the expected term of each grant.

(4)Risk-free interest rate is based on the yields of U.S. Treasury securities with maturities similar to the expected term of the share options in effect at the time of grant.

(5)Expected dividend is assumed to be 0% as ACM has no history or expectation of paying a dividend on its common stock.

Non-employee Award

The following table summarizes the ACM's non-employee share option activities during the years ended December 31, 2021, 2022 and 2023:


	Number of Option Shares (1)	Weighted Average Grant Date Fair Value (1)		Weighted Average Exercise Price (1)		Weighted Average Remaining Contractual Term
Outstanding at December 31, 2020	2,508,114	$	0.34	$	1.02	4.92 years
Exercised	(439,629)	0.37		1.28
Forfeited/cancelled	(1,467)	0.11		0.28
Outstanding at December 31, 2021	2,067,018	$	0.33	$	0.97	3.98 years
Exercised	(563,808)	0.21		0.51
Forfeited/cancelled	(19,552)	0.21		0.48
Outstanding at December 31, 2022	1,483,658	$	0.38	$	1.15	3.68 years
Exercised	(299,934)	0.24		0.55
Forfeited/cancelled	(12,929)	0.22		0.50
Outstanding at December 31, 2023	1,170,795	$	0.42	$	1.31	2.66 years
Vested and exercisable at December 31, 2023	1,167,045

As of December 31, 2023, $9 of total unrecognized non-employee stock-based compensation expense, net of estimated forfeitures, related to stock-based awards were both expected to be recognized over a weighted-average period of 0.20 year. Total recognized compensation cost may be adjusted for future changes in estimated forfeitures. The aggregate intrinsic value of options exercised in the years ended December 31, 2023, 2022 and 2021was $3,796, $9,110 and $11,993, respectively. The aggregate intrinsic value of options outstanding and exercisable as of December 31, 2023 were $21,342 and $21,301, respectively.

ACM Shanghai 2019 Option Grants

In January 2020, ACM Shanghai adopted a 2019 Stock Option Incentive Plan (the “2019 Subsidiary Stock Option Plan”) that provides for, among other incentives, the granting to officers, directors, employees of options to purchase shares of ACM Shanghai’s common stock. The vesting conditions consist of service periods conditions and performance conditions related to certain earning targets determined by the Board of Directors of ACM Shanghai.

The following table summarizes the ACM Shanghai employee stock option activities during the years ended December 31, 2023, 2022 and 2021 :


	Number of Option Shares in ACM Shanghai	Weighted Average Grant Date Fair Value		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term
Outstanding at December 31, 2020	5,423,654
Forfeited/cancelled	(46,154)	0.24		2.04		2.50 years
Outstanding at December 31, 2021	5,377,500	$	0.24	$	2.04	2.50 years
Outstanding at December 31, 2022	5,377,500	$	0.23	$	1.93	1.76 years
Exercised	(2,150,309)	0.20		1.85
Forfeited/cancelled	(92,308)	0.22		1.85
Outstanding at December 31, 2023	3,134,883	$	0.24	$	1.85	0.85 years
Vested and exercisable at December 31, 2023	492,308

ACM Shanghai 2023 Option Grants

In June 2023, ACM Shanghai adopted a 2023 Stock Option Incentive Plan ( the "2023 Subsidiary Stock Option Plan”) that provides for, among other incentives, the granting to officers, directors, employees of options to purchase shares of ACM Shanghai’s common stock. The vesting conditions consist of service periods conditions and performance conditions related to certain sales and research and development progress targets determined by the Board of Directors of ACM Shanghai.

The following table summarizes the ACM Shanghai 2023 Subsidiary Stock Option Plan’s stock option activities during the year ended December 31, 2023:


	Number of Option Shares in ACM Shanghai	Weighted Average Grant Date Fair Value		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term
Outstanding at December 31, 2022	—	$	—	$	—	0.00 years
Granted	10,648,500	$	9.49	$	7.06
Forfeited/cancelled	(73,000)	$	9.49	$	7.06	3.09 years
Outstanding at December 31, 2023	10,575,500	$	9.49	$	7.06	3.09 years
Vested and exercisable at December 31, 2023	—

The fair value of options granted to employees is estimated on the grant date using the Black-Scholes valuation with following assumptions:


			Year Ended December 31, 2023
Fair value of share of common stock (1)			$14.87
Expected term in years (2)			1.5-4.5
Volatility (3)			60.00%-60.60%
Risk-free interest rate (4)			1.50%-2.75%

(1) Equal to closing value on the grant date.

(2) Expected term of share options is based on the average of the vesting period and the contractual term for each grant.

(3) Volatility is calculated based on the historical volatility of ACM in the period equal to the expected term of each grant.

(4) Risk-free interest rate is based on the yields of RMB deposit in mainland China with maturities similar to the expected term of the share options in effect at the time of grant.

The aggregate intrinsic value of options outstanding as of December 31, 2023 was $81,981.

As of December 31, 2023, $79,882 of total unrecognized employee stock-based compensation expense, net of estimated forfeitures, related to ACM Shanghai stock-based awards were expected to be recognized over a weighted-average period of 2.1 years. Total recognized compensation cost may be adjusted for future changes in estimated forfeitures.

The following table summarizes the components of stock-based compensation expense included in the consolidated statements of comprehensive income (loss):


	Year Ended December 31,
	2023		2022		2021
Stock-Based Compensation Expense:
Cost of revenue	$	1,406	$	520	$	397
Sales and marketing expense	5,684		1,877		1,802
Research and development expense	8,459		2,565		1,115
General and administrative expense	11,789		2,768		1,803
	$	27,338	$	7,730	$	5,117


	Year Ended December 31,
	2023		2022		2021
Stock-based compensation expense by type:
Employee stock option plan	$	6,213	$	7,346	$	4,674
Non-employee stock option plan	46		46		94
2019 and 2023 Subsidiary stock option plans	21,079		338		349
	$	27,338	$	7,730	$	5,117

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities:
Net income	$ 96,852	$ 50,564	$ 42,921
Adjustments to reconcile net income from operations to net cash used in operating activities
Non-cash operating lease cost	3,580	2,816	2,451
Depreciation and amortization	8,092	5,366	2,353
Gain on disposals of property, plant and equipment	(2)	(12)	0
Realized gain on short-term investments	(9,047)	(1,116)	0
Income from equity method investments	(9,952)	(4,666)	(4,637)
Unrealized loss (gain) on short-term investments	2,737	7,855	(607)
Inventory provision	575	2,248	75
Provision for credit losses	2,741	0	0
Deferred income taxes	(13,647)	4,027	(1,840)
Stock-based compensation	27,338	7,730	5,117
Net changes in operating assets and liabilities:
Accounts receivable	(108,749)	(88,655)	(47,624)
Income tax recoverable	0	0	(1,082)
Other receivables	(4,213)	(7,331)	(8,420)
Inventories	(164,027)	(195,562)	(127,731)
Advances to related party (note 16)	890	(939)	(776)
Prepaid expenses	(5,075)	(3,695)	(9,830)
Other long-term assets	0	3,986	(4,521)
Related party accounts payable (note 16)	(3,061)	6,569	3,806
Accounts payable	42,343	17,501	61,405
Advances from customers	29,974	104,258	34,831
Deferred revenue	2,693	994	226
Income taxes payable	3,009	3,236	2,200
FIN-48 payable	5,463	4,404	10,551
Other payables and accrued expenses	21,375	23,406	3,180
Operating lease liabilities	(3,580)	(2,816)	(2,451)
Other long-term liabilities	(1,632)	(2,362)	310
Net cash used in operating activities	(75,323)	(62,194)	(40,093)
Cash flows from investing activities:
Purchase of property and equipment	(61,876)	(91,094)	(9,153)
Purchase of intangible assets	(2,462)	(1,426)	(559)
Purchase of long-term investments (note 14)	(7,508)	(5,279)	(1,568)
Purchase of short-term investments (note 15)	(18,356)	0	0
Purchase of time deposits	(26,120)	(172,448)	0
Proceeds from maturity of time deposits	79,600	0	0
Proceeds from sale of short-term investments (note 15)	21,735	4,577	0
Proceeds from disposal of long-term investments	8,242	0	0
Net cash used in investing activities	(6,745)	(265,670)	(11,280)
Cash flows from financing activities:
Proceeds from short-term borrowings	31,334	56,004	22,884
Repayments of short-term borrowings	(55,068)	(9,224)	(39,809)
Proceeds from long-term borrowings	42,360	0	7,056
Repayments of long-term borrowings	(2,283)	(2,223)	(2,127)
ACM Shanghai dividends	(3,951)	0	0
Proceeds from exercise of stock options	6,138	1,314	3,430
Proceeds from a subsidiary equity issuance, net of issuance costs	0	0	545,512
Proceeds from warrant exercise to common stock	0	0	1,820
Net cash provided by financing activities	18,530	45,871	538,766
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(1,740)	(32,623)	3,908
Net increase (decrease) in cash, cash equivalents and restricted cash	(65,278)	(314,616)	491,301
Cash, cash equivalents and restricted cash at beginning of period	248,451	563,067	71,766
Cash, cash equivalents and restricted cash at end of period	183,173	248,451	563,067
Supplemental disclosure of cash flow information:
Interest paid, net of capitalized interest	2,681	1,655	765
Cash paid for income taxes	26,103	3,586	1,132
Reconciliation of cash, cash equivalents and restricted cash in consolidated statements of cash flows:
Cash and cash equivalents	182,090	247,951	562,548
Restricted cash	1,083	500	519
Cash, cash equivalents and restricted cash	183,173	248,451	563,067
Non-cash financing activities:
Cashless exercise of stock options	333	221	137
Non-cash investing activities:
Transfer from inventory to property, plant and equipment	4,379	0	0
Purchase property, plant and equipment through accounts payable and other payable	33,750	0	0
Transfer of prepayment for property to property, plant and equipment	$ 0	$ 41,497	$ 0

Consolidated Balance Sheets (Parenthetical)	1 Months Ended
Consolidated Balance Sheets (Parenthetical)	Mar. 31, 2022
Stock split ratio	3
Class A Common Stock
Stock split ratio	3

OTHER PAYABLES AND ACCRUED EXPENSES (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Payables and Accruals [Abstract]
Accrued commissions	$ 15,572	$ 14,890
Accrued warranty	9,834	8,780	$ 6,631	$ 3,975
Accrued payroll	14,840	12,201
Accrued professional fees	696	724
Accrued machine testing fees	1,762	1,215
Accrued machine sales fees	6,010	5,874
Accrued Lingang construction fees	33,729	738
Others	20,508	7,779
Total	$ 102,951	$ 52,201

PARENT COMPANY ONLY CONDENSED FINANCIAL INFORMATION, Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Cash Flows [Abstract]
Net cash provided by (used in) operating activities	$ (75,323)	$ (62,194)	$ (40,093)
Net cash used in investing activities	(6,745)	(265,670)	(11,280)
Net cash provided by financing activities	18,530	45,871	538,766
Net increase (decrease) in cash, cash equivalents and restricted cash	(65,278)	(314,616)	491,301
Cash, cash equivalents and restricted cash at beginning of period	248,451	563,067	71,766
Cash, cash equivalents and restricted cash at end of period	183,173	248,451	563,067
Parent Company
Statement of Cash Flows [Abstract]
Net cash provided by (used in) operating activities	1,489	(5,997)	(5,902)
Net cash used in investing activities	(149)	(1,000)	0
Net cash provided by financing activities	16,423	1,314	5,250
Net increase (decrease) in cash, cash equivalents and restricted cash	17,763	(5,683)	(652)
Cash, cash equivalents and restricted cash at beginning of period	23,853	29,536	30,188
Cash, cash equivalents and restricted cash at end of period	$ 41,616	$ 23,853	$ 29,536

SEGMENT INFORMATION

12 Months Ended

Dec. 31, 2023

Segment Reporting [Abstract]

SEGMENT INFORMATION

The Company identifies operating segments according to how the business activities are managed and evaluated. The Company’s chief operating decision maker (“CODM”) has been identified as ACM’s Chief Executive Officer. The Company's operating segments include ACM Research and ACM Shanghai. As the Company is engaged in the developing, manufacture and sale of capital equipment to global semiconductor manufacturers, and each of the operating segments share similar economic and other qualitative characteristics, the results of the Company’s operating segments are aggregated into one reportable segment.

For geographical reporting, revenue by geographic location is determined by the location of customers’ facilities to which products were shipped. Long-lived assets consist primarily of property, plant and equipment, other long-term assets, and

right-of-use assets and are attributed to the geographic location in which they are located. Long-lived assets by geographic region as of the years ended were as follows:


	December 31,
	2023		2022
Long-lived assets by geography:
Mainland China	$	209,725	$	140,481
Korea	12,190		3,830
United States	1,276		10
Total	$	223,191	$	144,321

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-22

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-15

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 31
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-31

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-42

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 40
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-40

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//280/tableOfContent

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 26
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-26

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 34
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-34

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 41
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-41

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-21

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-21

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

+ Details

DESCRIPTION OF BUSINESS

12 Months Ended

Dec. 31, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

DESCRIPTION OF BUSINESS

ACM Research, Inc. (“ACM” or "ACM Research") and its subsidiaries (collectively with ACM, the “Company”) develop, manufacture and sell single-wafer wet cleaning equipment used to improve the manufacturing process and yield for advanced integrated chips. The Company markets and sells its single-wafer wet-cleaning equipment, under the brand name “Ultra C,” based on the Company’s proprietary Space Alternated Phase Shift (“SAPS”) and Timely Energized Bubble Oscillation (“TEBO”) technologies. These tools are designed to remove random defects from a wafer surface efficiently, without damaging the wafer or its features, even at increasingly advanced process nodes.

ACM was incorporated in California in 1998, and it initially focused on developing tools for manufacturing process steps involving the integration of ultra-low-K materials and copper. The Company’s early efforts focused on stress-free copper-polishing technology, and it sold tools based on that technology in the early 2000s.

In 2006, the Company established its operational center in Shanghai in the People’s Republic of China ("mainland China"), where it operates through ACM’s subsidiary, ACM Research (Shanghai), Inc. (“ACM Shanghai”). ACM Shanghai was formed to help establish and build relationships with integrated circuit manufacturers in mainland China, and the Company initially financed its Shanghai operations in part through sales of non-controlling equity interests in ACM Shanghai.

In 2007, the Company began to focus its development efforts on single-wafer wet-cleaning solutions for the front-end chip fabrication process. The Company introduced its SAPS megasonic technology, which can be applied in wet wafer cleaning at numerous steps during the chip fabrication process, in 2009. It introduced its TEBO technology, which can be applied at numerous steps during the fabrication of small node two-dimensional conventional and three-dimensional patterned wafers, in March 2016. The Company has designed its equipment models for SAPS and TEBO solutions using a modular configuration that enables it to create a wet-cleaning tool meeting the specific requirements of a customer, while using pre-existing designs for chamber, electrical, chemical delivery and other modules. In August 2018, the Company introduced its Ultra-C Tahoe wafer cleaning tool, which can deliver high cleaning performance with significantly less sulfuric acid than typically consumed by conventional high-temperature single-wafer cleaning tools. Based on its electro-chemical plating (“ECP”) technology, the Company introduced in March 2019 its Ultra ECP AP, or “Advanced Packaging,” tool for bumping, or applying copper, tin and nickel to semiconductor wafers at the die-level, and its Ultra ECP MAP, or “Multi-Anode Partial Plating,” tool to deliver advanced electrochemical copper plating for copper interconnect applications in front-end wafer fabrication processes. The Company also offers a range of custom-made equipment, including cleaners, coaters and developers, to back-end wafer assembly and packaging factories, principally in mainland China.

In 2011, ACM Shanghai formed a wholly owned subsidiary in mainland China, ACM Research (Wuxi), Inc. (“ACM Wuxi”), to manage sales and service operations.

In November 2016, ACM re-domesticated from California to Delaware pursuant to a merger in which ACM Research, Inc., a California corporation, was merged into a newly formed, wholly owned Delaware subsidiary, also named ACM Research, Inc.

In June 2017, ACM formed a wholly owned subsidiary in Hong Kong, CleanChip Technologies Limited (“CleanChip”), to act on the Company’s behalf in Asian markets outside mainland China by, for example, serving as a trading partner between ACM Shanghai and its customers, procuring raw materials and components, performing sales and marketing activities, and making strategic investments.

In August 2017, ACM purchased 18.77% of ACM Shanghai’s equity interests held by Shanghai Science and Technology Venture Capital Co., Ltd. On November 8, 2017, ACM purchased the remaining 18.36% of ACM Shanghai’s equity interest held by third parties, Shanghai Pudong High-Tech Investment Co., Ltd. (“PDHTI”) and Shanghai Zhangjiang Science & Technology Venture Capital Co., Ltd. (“ZSTVC”). At December 31, 2017, ACM owned all of the outstanding equity interests of ACM Shanghai, and indirectly through ACM Shanghai, owned all of the outstanding equity interests of ACM Wuxi.

On November 2, 2017, the Registration Statement on Form S-1 (File No. 333- 220451) for ACM’s initial public offering of Class A common stock (the “IPO”) was declared effective by the U.S. Securities and Exchange Commission. Shares of

Class A common stock began trading on the Nasdaq Global Market on November 3, 2017, and the closing for the IPO was held on November 7, 2017.

In December 2017, ACM formed a wholly owned subsidiary in the Republic of Korea (“Korea”), ACM Research Korea CO., LTD. (“ACM Korea”), to serve customers based in Korea and perform sales, marketing, research and development activities for new products and solutions.

In March 2019, ACM Shanghai formed a wholly owned subsidiary in mainland China, Shengwei Research (Shanghai), Inc. (“ACM Shengwei”), to manage activities related to the addition of future long-term production capacity.

In June 2019, CleanChip formed a wholly owned subsidiary in California, ACM Research (CA), Inc. (“ACM California”), to provide procurement services on behalf of ACM Shanghai.

In June 2019, ACM announced plans to complete over the next three years a listing (the “STAR Listing”) of shares of ACM Shanghai on the Shanghai Stock Exchange’s new SciTech innovAtion boaRd, known as the STAR Market, and a concurrent initial public offering (the “STAR IPO”) of ACM Shanghai shares in mainland China. ACM Shanghai is currently ACM’s primary operating subsidiary, and at the time of announcement, was wholly owned by ACM. To meet a STAR Listing requirement that it have multiple independent stockholders in mainland China, ACM Shanghai completed private placements of its shares in June and November 2019, following which, as of September 30, 2020, the private placement investors held a total of 8.3% of the outstanding shares of ACM Shanghai and ACM Research held the remaining 91.7%. As part of the STAR Listing process, in June 2020 the ownership interests held by the private investors were reclassified from redeemable non-controlling interests to non-controlling interests as the redemption feature was terminated. In preparation for the STAR IPO, ACM completed a reorganization in December 2020 that included the sale of all of the shares of CleanChip by ACM to ACM Shanghai for $3,500. The reorganization and sale had no impact on ACM’s consolidated financial statements.

In August 2021, ACM formed a wholly owned subsidiary in Singapore, ACM research (Singapore) PTE, Ltd. to perform sales, marketing, and other business development activities.

In November 2021, ACM’s operating subsidiary ACM Shanghai, completed its STAR IPO and its shares began trading on the STAR Market. In the STAR IPO, ACM Shanghai issued 43,355,753 shares, representing 10% of the total 433,557,100 shares outstanding after the issuance. The shares were issued at a public offering price of RMB 85.00 per share, and the net proceeds of the STAR IPO, after issuance costs, totaled $545,512. Upon completion of the STAR IPO, ACM owned 82.5% of the outstanding ACM Shanghai shares. However, in May 2023, ACM's ownership declined to 82.1% due to the exercise of 2,150,309 stock options related to ACM Shanghai shares.

In February 2022, ACM Shanghai formed a wholly owned subsidiary in China, ACM Research (Beijing), Inc. (“ACM Beijing”), to perform sales, marketing and other business development activities.

In March 2022, ACM formed a wholly owned subsidiary in Korea, Hanguk ACM CO., LTD, to perform business development and other related activities.

In March 2022, the Board of Directors of ACM declared a 3-for-1 stock split of Class A and Class B common stock effected in the form of a stock dividend (the “Stock Split”). Each stockholder of record at the close of business on March 16, 2022, received a dividend of two additional shares of Class A common stock for each then-held share of Class A common stock and two additional shares of Class B common stock for each then-held share of Class B common stock, which were distributed after the close of trading on March 23, 2022. Unless otherwise indicated, all share numbers, per share amount, share prices, exercise prices and conversion rates set forth in these notes and the accompanying consolidated financial statements have been adjusted retrospectively to reflect the Stock Split.

In June 2023, ACM Shanghai formed a wholly-owned subsidiary in mainland China, Yusheng Micro Semiconductor (Shanghai), Co., Ltd, ("Yusheng Micro") to perform business development activities.

In June 2023, Yusheng Micro together with Wooil Flucon Co. (note 14) and a private investor established ACM-Wooil Microelectronics (Shanghai) Co., Ltd, ("ACM-Wooil"), a partially owned subsidiary based in mainland China to develop and produce key components for the semiconductor equipment industry.

The Company has direct or indirect interests in the following subsidiaries:


	Place and date of incorporation	Effective interest held as at December 31,
Name of subsidiaries		2023	2022
ACM Research (Shanghai), Inc.	Mainland China, May 2005	82.1%	82.5%
ACM Research (Wuxi), Inc.	Mainland China, July 2011	82.1%	82.5%
CleanChip Technologies Limited	Hong Kong, June 2017	82.1%	82.5%
ACM Research Korea CO., LTD.	Korea, December 2017	82.1%	82.5%
ACM Research (Lingang), Inc. (1)	Mainland China, March 2019	82.1%	82.5%
ACM Research (CA), Inc.	USA, April 2019	82.1%	82.5%
ACM Research (Cayman), Inc.	Cayman Islands, April 2019	100.0%	100.0%
ACM Research (Singapore) PTE. Ltd.	Singapore, August 2021	100.0%	100.0%
ACM Research (Beijing), Inc.	Mainland China, February 2022	82.1%	82.5%
Hanguk ACM CO., LTD	Korea, March 2022	100.0%	100.0%
Yusheng Micro Semiconductor (Shanghai) Co., Ltd.	Mainland China, June 2023	82.1%	-
ACM-Wooil Microelectronics (Shanghai) Co., Ltd.	Mainland China, June 2023	59.4%	-

(1) ACM Research (Lingang) Inc., or ACM Lingang, is the English name referred to by its Chinese language name Shengwei Research (Shanghai), Inc. in prior filings. ACM Research (Lingang), Inc. and Shengwei Research (Shanghai), Inc. refer to the same entity.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Warranty (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Warranty Obligations [Roll Forward]
Balance at beginning of period	$ 8,780	$ 6,631	$ 3,975
Additions	7,969	5,379	5,026
Utilized	(6,915)	(3,230)	(2,370)
Balance at end of period	$ 9,834	$ 8,780	$ 6,631
Minimum
Standard Product Warranty Disclosure [Abstract]
Standard assurance type warranty period	12 months
Maximum
Standard Product Warranty Disclosure [Abstract]
Standard assurance type warranty period	36 months

LAND USE RIGHT, NET

12 Months Ended

Dec. 31, 2023

LAND USE RIGHT, NET [Abstract]

LAND USE RIGHT, NET

A summary of land use right is as follows:


	December 31,
	2023		2022
Land use right purchase amount	$	8,996	$	9,149
Less: accumulated amortization	(629)		(457)
Land use right, net	$	8,367	$	8,692

The amortization for the years ended December 31, 2023, 2022 and 2021 was $181, $189 and $199, respectively.

The annual amortization of land use right for each of the five succeeding years is as follows:


Year ending December 31,
2024	$	180
2025	180
2026	180
2027	180
2028	180
2029 and thereafter	7,467
Total	$	8,367

COMMON STOCK (Details)	1 Months Ended	12 Months Ended
COMMON STOCK (Details)	Mar. 31, 2022	Dec. 31, 2023 shares $ / shares	Dec. 31, 2022 $ / shares shares	Dec. 31, 2021 shares	Mar. 16, 2022 shares	Dec. 31, 2020 shares
Class of Stock Disclosures [Abstract]
Stock split ratio	3
Common Stock Class A
Class of Stock Disclosures [Abstract]
Common stock, shares authorized (in shares)		150,000,000	150,000,000
Common stock, par value (in dollars per share) \| $ / shares		$ 0.0001	$ 0.0001
Number of votes for each share entitled		1
Stock split ratio	3
Additional shares reserved for issuance as dividends (in shares)					2
Common stock, shares issued (in shares)		56,036,172	54,655,286
Common stock, shares outstanding (in shares)		56,036,172	54,655,286
Class B Common Stock
Class of Stock Disclosures [Abstract]
Common stock, shares authorized (in shares)		5,307,816	5,307,816
Common stock, par value (in dollars per share) \| $ / shares		$ 0.0001	$ 0.0001
Number of votes for each share entitled		20
Conversion of stock, converted (in shares)		1
Additional shares reserved for issuance as dividends (in shares)					2
Common stock, shares issued (in shares)		5,021,811	5,021,811
Common stock, shares outstanding (in shares)		5,021,811	5,021,811
Common Stock \| Common Stock Class A
Class of Stock Disclosures [Abstract]
Exercise of stock options (in shares)		1,380,886	980,354	1,870,803
Conversion of class B common shares to Class A common shares (in shares)			66,003	320,004
Exercise of warrants (in shares)				728,043
Common stock, shares outstanding (in shares)		56,036,172	54,655,286	53,608,929		50,690,079
Common Stock \| Class B Common Stock
Class of Stock Disclosures [Abstract]
Conversion of class B common shares to Class A common shares (in shares)			(66,003)	(320,004)
Common stock, shares outstanding (in shares)		5,021,811	5,021,811	5,087,814		5,407,818

COMMITMENTS AND CONTINGENCIES	12 Months Ended
COMMITMENTS AND CONTINGENCIES	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES The Company leases offices and manufacturing locations under non-cancelable operating lease agreements. See note 11 for future minimum lease payments under non-cancelable operating lease agreements with initial terms of one year or more. As of December 31, 2023, the Company had $30,936 of open commitments to construction contracts and had additional $7,413 of capital investment commitments. Covenants in ACM Shengwei’s Grant Contract for State-owned Construction Land Use Right in Shanghai City (Category of R&D Headquarters and Industrial Projects) with the China (Shanghai) Pilot Free Trade Zone Lingang Special Area Administration require, among other things, that ACM Shengwei pay liquidated damages in the event that (a) it does not make a total investment (including the costs of construction, fixtures, equipment and grant fees) of at least RMB 450.0 million ($63,400) or (b) within six years after the land use right is obtained, the Company does not (i) generate a minimum specified amount of annual sales of products manufactured on the granted land or (ii) pay to mainland China at least RMB 157.6 million ($22,000) in annual total taxes (including value-added taxes, corporate income tax, personal income taxes, urban maintenance and construction taxes, education surcharges, stamp taxes, and vehicle and shipping taxes) as a result of operations in connection with the granted land. As of December 31, 2023 and December 31, 2022, the Company had incurred in total $116,932 and $35,376, respectively for its Lingang-related investments. The Construction Completion Milestone was required to be met by January 9, 2024 but was not achieved. However, ACM Lingang believes it will receive the refund without penalty based on its explanation to the respective regulatory authorities of logistics-related delays, and expectations that it will meet the milestone before July 9, 2024. The Company cannot guarantee that ACM Lingang will achieve the missed milestone in 2024, or even if it does achieve the milestone in 2024, that it will be refunded some or all of the 20% portion of the performance deposit of RMB 2.5 million ($0.4 million). In the normal course of business, the Company is subject to contingencies, including legal proceedings and environmental claims arising out of the normal course of businesses that relate to a wide range of matters, including among others, contracts breach liability. The Company records accruals for such contingencies based upon the assessment of the probability of occurrence and, where determinable, an estimate of the liability. Management may consider many factors in making these assessments including past history, scientific evidence and the specifics of each matter. Some of these contingencies involve claims that are subject to substantial uncertainties and unascertainable damages. The Company’s management has evaluated all such proceedings and claims that existed as of December 31, 2023 and 2022. In the opinion of management, no provision for liability nor disclosure was required as of December 31, 2023 related to any claim against the Company because: (a) there is not a reasonable possibility that a loss exceeding amounts already recognized (if any) may be incurred with respect to such claim; (b) a reasonably possible loss or range of loss cannot be estimated; or (c) such estimate is immaterial. As of December 31, 2023, the Company had no outstanding legal proceedings.

INVENTORIES (Details) - USD ($) $ in Thousands	12 Months Ended
INVENTORIES (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Inventory [Abstract]
Raw materials	$ 235,062	$ 167,135
Work-in-process	81,438	79,126
Finished goods	228,895	146,911
Total inventory	545,395	393,172
Increase in raw materials and work in process	70,239
Increase in finished goods	$ 81,984
Period in which raw materials are considered impaired	3 years
Inventory write-down	$ 575	2,248	$ 75
First-Tools, Customer Ownership
Inventory [Abstract]
Finished goods	$ 123,390	$ 123,169

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)

12 Months Ended

Dec. 31, 2023

Accounting Policies [Abstract]

Cash and Cash Equivalents

The following table presents cash and cash equivalents, according to jurisdiction as of December 31, 2023 and 2022:


	December 31,
	2023		2022
United States	$	43,614	$	25,011
Mainland China	70,418		129,695
China Hong Kong	64,057		89,187
Korea	3,934		4,007
Singapore	67		51
Total	$	182,090	$	247,951

Summary of Time Deposits


	December 31,
	2023		2022
Deposit in China Merchant Bank which matured on January 29, 2023 with an annual interest rate of 2.25%	$	—	$	38,772
Deposit in China Everbright Bank which matured on January 29, 2023 with an annual interest rate of 2.25%	—		14,360
Deposit in China Everbright Bank which matured on May 22, 2023 with an annual interest rate of 5.07%	—		3,000
Deposit in China Industrial Bank which matured on January 30, 2023 with an annual interest rate of 2.15%	—		14,360
Deposit in China Merchant Bank which matured on January 29, 2024 with an annual interest rate of 2.85%	29,797		28,720
Deposit in Bank of Ningbo which matured on February 17, 2024 with an annual interest rate of 2.85%	44,630		43,080
Deposit in Shanghai Pudong Development Bank which matures on October 20, 2025 with an annual interest rate of 3.10%	7,322		7,180
Deposit in Shanghai Pudong Development Bank which matures on November 14, 2025 with an annual interest rate of 3.10%	7,307		7,180
Deposit in Shanghai Pudong Development Bank which matures on December 8, 2025 with an annual interest rate of 3.10%	4,376		4,308
Deposit in Shanghai Pudong Development Bank which matures on December 15, 2025 with an annual interest rate of 3.10%	4,373		4,308
Deposit in Shanghai Pudong Development Bank which matures on December 30, 2025 with an annual interest rate of 3.10%	2,912		7,180
Deposit in China Industrial Bank which matures on January 30, 2026 with an annual interest rate of 3.15%	14,528		—
Deposit in China Everbright Bank which matured on January 5, 2024 with an annual interest rate of 5.38%	3,079		—
Deposit in China Everbright Bank which matures on May 22, 2024 with an annual interest rate of 5.38%	3,018		—
	$	121,342	$	172,448

Estimated Useful Lives of Property, Plant and Equipment

Estimated useful lives of assets are as follows:


Buildings and plants			30 years
Computer and office equipment			3 to 5 years
Furniture and fixtures			5 years
Leasehold improvements			shorter of lease term or estimated useful life
Electronic equipment			3 to 5 years
Manufacturing equipment			for small to medium-sized equipment, 5 to 10 years; for large equipment, estimated by purchasing department at time of acceptance
Transportation equipment			4 to 5 years

Warranty Obligations

The following table shows changes in the Company’s warranty obligations for the years ended December 31, 2023, 2022 and 2021, respectively.


	Year Ended December 31,
	2023		2022		2021
Balance at beginning of period	$	8,780	$	6,631	$	3,975
Additions	7,969		5,379		5,026
Utilized	(6,915)		(3,230)		(2,370)
Balance at end of period	$	9,834	$	8,780	$	6,631

Basic and Diluted Net Income per Common Share

Basic and diluted net income per share of common stock is calculated as follows:


	Year Ended December 31,
	2023		2022		2021
Numerator:
Net income	$	96,852	$	50,564	$	42,921
Less: Net income attributable to non-controlling interests	19,503		11,301		5,164
Net income available to common stockholders, basic	$	77,349	$	39,263	$	37,757
Less: Dilutive effect arising from stock-based awards by ACM Shanghai	1,841		584		108
Net income available to common stockholders, diluted	$	75,508	$	38,679	$	37,649
Weighted average shares outstanding, basic (1)	60,164,670		59,235,975		57,654,708
Effect of dilutive securities	4,705,873		6,105,796		7,702,008
Weighted average shares outstanding, diluted	64,870,543		65,341,771		65,356,716

Net income per share of common stock:
Basic	$	1.29	$	0.66	$	0.65
Diluted	$	1.16	$	0.59	$	0.58

(1)The results for 2021 have been adjusted to reflect the three-for-one stock split effected in the form of a stock dividend in March 2022. See Note 2 for details.

Carrying Value of Borrowings

Assets and liabilities measured at fair value on a recurring basis:


	Quoted Prices in Active Markets for Identical Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
As of December 31, 2023
Assets
Cash and cash equivalents	$	182,090	$	-	$	-	$	182,090
Short-term investments	21,312		-		-		21,312
	$	203,402	$	-	$	-	$	203,402

As of December 31, 2022
Assets
Cash and cash equivalents	$	247,951	$	-	$	-	$	247,951
Short-term investments	20,209		-		-		20,209
	$	268,160	$	-	$	-	$	268,160

Assets and liabilities measured at fair value on a non-recurring basis:


	Quoted Prices in Active Markets for Identical Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
As of December 31, 2023
Assets
Investments accounted for using measurement alternative	$	—	$	—	$	10,378	$	10,378
	$	—	$	—	$	10,378	$	10,378

OTHER LONG-TERM ASSETS (Details) ¥ in Thousands, $ in Thousands	Dec. 31, 2023 USD ($)	Dec. 31, 2023 CNY (¥)	Feb. 28, 2023 USD ($)	Feb. 28, 2023 CNY (¥)	Dec. 31, 2022 USD ($)
Other Long-term Assets [Abstract]
Prepayment for property, plant and equipment	$ 3,380				$ 704
Lease deposit	834				393
Security deposit for land use right	696				708
Others	1,140				1,209
Total other long-term assets	6,050				50,265
Total cost	112,911				56,433
Zhangjiang
Other Long-term Assets [Abstract]
Prepayment for property - Zhangjiang New Building	0				47,251
Buildings and plants
Other Long-term Assets [Abstract]
Total cost	83,109				$ 35,864
Buildings and plants \| Shengwei Research (Shanghai), Inc.
Other Long-term Assets [Abstract]
Total cost	$ 35,264	¥ 249,746	$ 47,201	¥ 338,848

INCOME TAXES - Summary of Effective Income Tax Rate (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income tax provision at statutory rate	21.00%	21.00%	21.00%
Stock Compensation	(2.00%)	(2.72%)	(12.75%)
Foreign rate differential	(10.47%)	(9.43%)	(11.60%)
Other permanent difference	0.03%	(0.26%)	(0.23%)
Foreign income taxed in US	7.39%	19.86%	10.32%
Foreign Research Expense	(8.01%)	(4.79%)	(6.59%)
Change in valuation allowance	8.72%	1.28%	0.16%
Total income tax expense	16.66%	24.94%	0.31%

COMMITMENTS AND CONTINGENCIES (Details) $ in Thousands, ¥ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2023 CNY (¥)	Dec. 31, 2023 CNY (¥)	Dec. 31, 2022 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Contractual obligation	$ 30,936
Other commitment	7,413
Damages awarded	$ 63,400	¥ 450.0
Land use rights period	6 years	6 years
Annual total taxes	$ 22,000	¥ 157.6
Investments	116,932			$ 35,376
Security Deposit	$ 400		¥ 2.5
Security deposit refund (as a percent)	20.00%		20.00%

OTHER PAYABLES AND ACCRUED EXPENSES

12 Months Ended

Dec. 31, 2023

Payables and Accruals [Abstract]

OTHER PAYABLES AND ACCRUED EXPENSES

At December 31, 2023 and 2022, other payables and accrued expenses consisted of the following:


	December 31,
	2023		2022
Accrued commissions	$	15,572	$	14,890
Accrued warranty	9,834		8,780
Accrued payroll	14,840		12,201
Accrued professional fees	696		724
Accrued machine testing fees	1,762		1,215
Accrued machine sales fees	6,010		5,874
Accrued Lingang construction fees	33,729		738
Others	20,508		7,779
Total	$	102,951	$	52,201

INCOME TAXES

12 Months Ended

Dec. 31, 2023

Income Tax Disclosure [Abstract]

INCOME TAXES

The following represent the U.S. and foreign components of income before income tax for the years ended December 31, 2023, 2022 and 2021:


	Year Ended December 31,
	2023		2022		2021
U.S. federal	$	10,420	$	(3,456)	$	(4,389)
Foreign	105,796		70,818		47,444
Income before income taxes	$	116,216	$	67,362	$	43,055

The following represent components of the income tax benefit (expense) for the years ended December 31, 2023, 2022 and 2021:


	Year Ended December 31,
	2023		2022		2021
Current:
U.S. federal	$	(12,757)	$	(479)	$	(91)
U.S. state	(150)		(18)		(2)
Total U.S. current tax benefit (expense)	(12,907)		(497)		(93)
Foreign	(19,696)		(11,139)		(2,195)
Total current tax expense	(32,603)		(11,636)		(2,288)
Deferred:
U.S. federal	7,316		(10,927)		2,089
U.S. state	63		8		-
Total U.S. deferred tax benefit (expense)	7,379		(10,919)		2,089
Foreign	5,860		5,757		65
Total deferred tax benefit	13,239		(5,162)		2,154
Total income tax expense	$	(19,364)	$	(16,798)	$	(134)

Tax effects of temporary differences that give rise to significant portions of the Company’s deferred tax assets at December 31, 2023 and 2022 are presented below:


	December 31,
	2023		2022

Deferred tax assets:
Net operating loss carry forwards (offshore)	$	11,499	$	1,456
Net operating loss carry forwards (U.S.) and credit	4,930		1,246
Deferred revenue (offshore)	2,277		1,826
Accruals (U.S.)	3,632		100
Reserves and other (offshore)	4,662		3,655
Stock-based compensation (U.S.)	2,455		2,060
Stock-based compensation (offshore)	4,393		1,229
Lease liability	1,252		414
Total gross deferred tax assets	35,100		11,986
Less: valuation allowance	(11,917)		(1,782)
Total deferred tax assets	23,183		10,204
Deferred tax liabilities:
Fixed assets	(1,325)		(443)
Equity Investments and unrealized gain on short-term investments	(1,587)		(3,059)
Total deferred tax liabilities	(2,912)		(3,502)
Deferred tax assets, net	$	20,271	$	6,702

The Company considers all available evidence to determine whether it is more likely than not that some portion or all of the deferred tax assets will be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become realizable. Management considers the scheduled reversal of deferred tax liabilities (including the impact of available carryback and carry-forward periods), and projected taxable income in assessing the realizability of deferred tax assets. In making such judgments, significant weight is given to evidence that can be objectively verified. Based on all available evidence, a partial valuation allowance

has been established against some net deferred tax assets as of December 31, 2023 and 2022, based on estimates of recoverability. In order to fully realize the deferred tax assets, the Company must generate sufficient taxable income in future periods before the expiration of the deferred tax assets governed by the tax code.

As of December 31, 2023 and 2022, the Company had valuation allowances, respectively, of $29 and $49 for U.S. federal purposes, $279 and $277 for U.S. state purposes and $11,585 and $1,456 for mainland China income tax purposes.

As of December 31, 2023 and 2022, the Company had net operating loss carry-forwards of, respectively, $3,121 and $4,385 for U.S. federal purposes, $593 and $545 for U.S. state purposes and $46,467 and $6,474 for mainland China income tax purposes. Such losses begin expiring in 2036, 2032 and 2025 for U.S. federal, U.S. state and mainland China income tax purposes, respectively.

Under provisions of the U.S. Internal Revenue Code (the “IRC”), a limitation applies to the use of the U.S. net operating loss and credit carry-forwards that would be applicable if ACM experiences an “ownership change,” as defined in IRC Section 382. ACM conducted an analysis of its stock ownership under IRC Section 382 and $3,121 of the net operating loss carryforwards are subject to annual limitation as a result of the ownership change in 2017. The net operating loss carryforwards are not expected to expire before utilization.

The Company’s effective tax rate differs from statutory rates of 21% for U.S. federal income tax purposes and 12.5% to 25% for mainland China income tax purpose due to the effects of the valuation allowance and certain permanent differences as they pertain to book-tax differences in employee stock-based compensation and non-US research expense. A new requirement to capitalize and amortize previously deductible research and experimental expenses resulting from a change in Section 174 made by the Tax Cuts and Jobs Act of 2017 (the “TCJA”) became effective on January 1, 2022. Under the TCJA, the Company is required to capitalize, and subsequently amortize R&D expenses over fifteen years for research activities conducted outside of the U.S. The capitalization of overseas R&D expenses resulted in a significant increase in the Company’s global intangible low-taxed income inclusion beginning in 2022. Pursuant to the Corporate Income Tax Law of mainland China, all of the Company’s mainland China subsidiaries are liable to mainland China Corporate Income Taxes at a rate of 25%, except for ACM Shanghai and ACM Lingang. According to Guoshuihan 2009 No. 203, an entity certified as an “advanced and new technology enterprise” is entitled to a preferential income tax rate of 15%. ACM Shanghai was certified as an “advanced and new technology enterprise” in 2012 and again in 2016, 2018, and 2021, effective until December 31, 2023, and is expected to be re-certified for future years in 2024. In 2022, ACM Shanghai was certified as an eligible integrated circuit production enterprise and was entitled to a preferential income tax rate of 12.5% from January 1, 2020 to December 31, 2022. Certain entities which meet requirements according to the Policy of the Lingang New area in China (Shanghai) Pilot Free Trade Zone are entitled to a preferential income tax rate of 15%. ACM Lingang was certified for this in 2021, and this preferential income tax rate is valid from January 1, 2020 until December 31, 2024. The provision for mainland China corporate income tax for ACM Shanghai is calculated by applying the income tax rate of 15% for the year ended December 31, 2023 and 12.5% for the years ended December 31, 2022 and 2021.

Income tax expense for the years ended December 31, 2023, 2022 and 2021 differed from the amounts computed by applying the statutory U.S. federal income tax rate of 21% to pretax income as a result of the following:


	Year Ended December 31,
	2023		2022		2021

Effective tax rate reconciliation:
Income tax provision at statutory rate	21.00	%	21.00	%	21.00	%
Stock Compensation	(2.00)		(2.72)		(12.75)
Foreign rate differential	(10.47)		(9.43)		(11.60)
Other permanent difference	0.03		(0.26)		(0.23)
Foreign income taxed in US	7.39		19.86		10.32
Foreign Research Expense	(8.01)		(4.79)		(6.59)
Change in valuation allowance	8.72		1.28		0.16
Total income tax expense	16.66	%	24.94	%	0.31	%

Tax positions are evaluated in a two-step process. The Company first determines whether it is more likely than not that a tax position will be sustained upon examination. If a tax position meets the more-likely-than-not recognition threshold it is then measured to determine the amount of benefit to recognize in the financial statements. The tax position is measured as the largest amount of benefit that is greater than 50% likely of being realized upon ultimate settlement. The aggregate changes in the balance of gross unrecognized tax benefits, which excludes interest and penalties, for the years ended December 31, 2023 and 2022, were as follows:


	Year Ended December 31,
	2023		2022		2021

Beginning balance	$	8,448	$	6,066	$	570
Increase of unrecognized tax benefits taken in prior years	199		—		52
Increase of unrecognized tax benefits related to current year	4,379		2,623		5,476
Reductions for tax positions related to prior years	—		(241)		(32)
Ending balance	$	13,026	$	8,448	$	6,066

The Company is subject to taxation in the United States, state, and foreign jurisdictions. All tax returns will remain open for examination by the federal and state authorities for three and four years, respectively, from the date of utilization of any net operating loss or credits. Certain tax years are subject to foreign income tax examinations by tax authorities until the statute of limitations expire.

The Company had $13,026 and $8,448 of unrecognized tax benefits as of December 31, 2023 and 2022, respectively.

The Company recognizes interest and penalties related to uncertain tax positions in income tax expense. As of December 31, 2023 and 2022, respectively, the Company had $1,667 and $508 of accrued penalties related to uncertain tax positions, all of which was recognized in the Company’s consolidated statements of comprehensive income (loss) for the year then ended. The amount of the unrecognized tax benefit that, if recognized, would impact the effective tax rate was $12,943 as of December 31, 2023. There were no ongoing examinations by taxing authorities as of December 31, 2023 or 2022.

Prior to the Tax Cuts and Jobs Act of 2017 (the "Tax Act"), the Company asserted that all unremitted earnings of its foreign subsidiaries were considered indefinitely reinvested. As a result of the Tax Act, the Company reported and paid U.S. tax on the majority of its previously unremitted foreign earnings, and repatriations of foreign earnings will generally be free of U.S. federal tax, but may incur other taxes such as withholding or state taxes. As of December 31, 2023, the Company has not made a provision for U.S. or additional foreign withholding taxes on approximately $130 million of undistributed earnings of its foreign subsidiaries that is indefinitely reinvested. Generally, such amounts become subject to U.S. taxation upon the remittance of dividends and under certain other circumstances.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//740/tableOfContent

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-14

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-21

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 270
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482526/740-270-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 17
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-17

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I.5.Q1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479360/740-10-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479360/740-10-S99-2

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482603/740-30-50-2

+ Details

PARENT COMPANY ONLY CONDENSED FINANCIAL INFORMATION, Condensed Statements of Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Statement [Abstract]
Revenue	$ 557,723	$ 388,832	$ 259,751
Cost of revenue	(281,508)	(205,217)	(144,895)
Gross profit	276,215	183,615	114,856
Operating expenses:
Sales and marketing expenses	(47,019)	(39,889)	(26,733)
General and administrative expenses	(40,648)	(22,465)	(15,214)
Research and Development Expense	(92,709)	(62,226)	(34,207)
Income from operations	95,839	59,035	38,702
Equity in earnings of consolidated subsidiaries and equity method investees	9,952	4,666	4,637
Interest income	8,354	8,740	505
Interest expense, net	(2,681)	(1,655)	(765)
Income before income taxes	116,216	67,362	43,055
Income tax benefit	(19,364)	(16,798)	(134)
Net income attributable to ACM Research, Inc.	77,349	39,263	37,757
Parent Company
Income Statement [Abstract]
Revenue	6,354	569	16
Cost of revenue	(4,336)	0	0
Gross profit	2,018	569	16
Operating expenses:
Sales and marketing expenses	(4,715)	(3,193)	(2,443)
General and administrative expenses	(7,840)	(5,421)	(5,116)
Income from operations	(10,537)	(8,045)	(7,543)
Equity in earnings of consolidated subsidiaries and equity method investees	73,707	32,145	43,866
Interest income	799	57	54
Interest expense, net	(66)	(7)	0
Other income, net	18,476	2,148	1,380
Income before income taxes	82,379	26,298	37,757
Income tax benefit	5,030	(12,965)	0
Net income attributable to ACM Research, Inc.	$ 77,349	$ 39,263	$ 37,757

LEASES - Operating Leases Discount Rate And Weighted Average Remaining Term (Details)	Dec. 31, 2023	Dec. 31, 2022
Lessee, Operating Lease, Description [Abstract]
Weighted average remaining term (in years)	3 years 5 months 8 days	2 years
Weighted average discount rate, percent	3.91%	4.25%

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Comprehensive Income Attributable to the Company (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Comprehensive income (loss):
Comprehensive income (loss) attributable to the Company	$ 68,546	$ (10,392)	$ 42,009

SHORT-TERM INVESTMENTS

12 Months Ended

Dec. 31, 2023

Investments, Debt and Equity Securities [Abstract]

SHORT-TERM INVESTMENTS

Pursuant to a Partnership Agreement dated June 9, 2020 (the “Partnership Agreement”) and a Supplementary Agreement thereto dated June 15, 2020 (the “Supplementary Agreement”), ACM Shanghai acquired shares of SMIC in July 2020. Shares of SMIC are listed on the STAR Market.

Pursuant to an Agreement entered into on September 19, 2022 (the ‘‘Agreement’’), ACM Shanghai became a limited partner of the Nuode Asset Fund Pujiang No. 783 Single Asset Management Plan (‘‘Nuode Asset Fund’’), a Chinese limited partnership formed by Nuode Asset Management Co., Ltd, a financial services firm based in Shanghai, China. Nuode Asset Fund was formed to establish a special fund with the purpose to participate in certain technology related investments in mainland China. Subsequent to the future purchase, any investment will be held by Nuode Asset Fund and restricted for a minimum period of nine months. The limited partners of the Nuode Asset Fund contributed a $22,160 to the fund, of which ACM Shanghai contributed $4,196, or 18.75% of the contribution on September 27, 2022.

In December 2022, the Nuode Asset Fund purchased shares in the secondary stock offering of a publicly traded mainland China-stock listing. The number of shares owned by Nuode Asset Fund was apportioned to all of the limited partners in proportion to their respective capital contributions which is 18.75% in the case of ACM Shanghai.

Pursuant to a Share Purchase Agreement dated June 2023, ACM Shanghai acquired shares of Huahong Semiconductor Limited (“Huahong”) in July 2023 with amount of $13,930. The shares held by ACM Shanghai are restricted for sale for a minimum period of twelve months. Huahong completed it STAR IPO in August 2023.

Pursuant to a Share Purchase Agreement dated August 2023, ACM Shanghai acquired shares of Zhongjuxin Limited Company (“Zhongjuxin”) in September 2023 with amount of RMB $4,179. The shares held by ACM Shanghai are restricted for sale for a minimum period of twelve months. Zhongjuxin completed it STAR IPO in September 2023.

The components of short-term investments were as follows:


	December 31,
	2023		2022
Short-term investments listed in Shanghai Stock Exchange
Cost	$	20,155	$	14,779
Market value	$	21,312	$	20,209

ACCOUNTS RECEIVABLE - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)
Accounts receivable [Abstract]
Increase in accounts receivable	$ 100,250
Increase in revenue	$ 168,891

OTHER LONG-TERM ASSETS

12 Months Ended

Dec. 31, 2023

Other Assets, Noncurrent Disclosure [Abstract]

OTHER LONG-TERM ASSETS

At December 31, 2023 and 2022, other long-term assets consisted of the following:


	December 31,
	2023		2022
Prepayment for property, plant and equipment	$	3,380	$	704
Lease deposit	834		393
Security deposit for land use right	696		708
Prepayment for property - Zhangjiang New Building	—		47,251
Others	1,140		1,209
Total other long-term assets	$	6,050	$	50,265

Prepayment for property - Zhangjiang New Building is for the new corporate headquarters of ACM Shanghai. Pursuant to contractual agreements, ownership of Zhangjiang New Building was transferred to ACM Shanghai in February 2023 at value of RMB 338,848 ($47,201). Upon the transfer of ownership, Prepayment for property - Zhangjiang New Building was reclassified to property, plant and equipment (Note 6).

LONG-TERM INVESTMENTS - Additional Information (Details) $ / shares in Units, ¥ in Thousands, $ in Thousands		12 Months Ended
	Sep. 05, 2019 investor	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Nov. 30, 2023 USD ($)	Nov. 30, 2023 CNY (¥)	Sep. 30, 2023 USD ($)	Sep. 30, 2023 CNY (¥)	Aug. 17, 2022	Oct. 29, 2021 USD ($)	Aug. 17, 2021 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2020 CNY (¥)	Jun. 27, 2019 USD ($)	Sep. 11, 2017 USD ($) $ / shares shares
Investments [Abstract]
Income from equity method investments		$ 9,952	$ 4,666	$ 4,637
Upward price adjustment		$ 1,465	$ 0	$ 0
Ninebell
Investments [Abstract]
Ownership percentage															20.00%
Equity method investment, aggregate cost															$ 1,200
Ninebell \| Class A Common Stock
Investments [Abstract]
Equity method investment, aggregate cost															$ 1,000
Shares issued (in shares) \| shares															400,002
Shares issued (in dollars per share) \| $ / shares															$ 2.50
Shengyi
Investments [Abstract]
Ownership percentage														15.00%
Investment - equity method							$ 900	¥ 6,100						$ 109
Hefei Shixi
Investments [Abstract]
Number of investors with agreements entered \| investor	6
Investment in partnership												$ 4,200	¥ 30,000
Ownership percentage in partnership												10.00%	10.00%
Waferworks
Investments [Abstract]
Ownership percentage										0.25%
Investment - equity method										$ 1,568
Wooil
Investments [Abstract]
Ownership percentage									20.00%
Investment - equity method											$ 1,000
Company A
Investments [Abstract]
Ownership percentage							4.37%	4.37%
Investment - equity method							$ 4,200	¥ 30,000
Company B
Investments [Abstract]
Ownership percentage					1.38%	1.38%
Investment - equity method					$ 930	¥ 6,600

OTHER LONG-TERM ASSETS (Tables)

12 Months Ended

Dec. 31, 2023

Other Assets, Noncurrent Disclosure [Abstract]

Other Long-term Assets

At December 31, 2023 and 2022, other long-term assets consisted of the following:


	December 31,
	2023		2022
Prepayment for property, plant and equipment	$	3,380	$	704
Lease deposit	834		393
Security deposit for land use right	696		708
Prepayment for property - Zhangjiang New Building	—		47,251
Others	1,140		1,209
Total other long-term assets	$	6,050	$	50,265

Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cost of revenue, related party	$ 281,508	$ 205,217	$ 144,895
Related Party
Cost of revenue, related party	$ 31,240	$ 26,313

- Definition

The aggregate cost of goods produced and sold and services rendered during the reporting period.

+ References

+ Details

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Statement [Abstract]
Revenue	$ 557,723	$ 388,832	$ 259,751
Cost of revenue, including cost of revenue from related party of $31,240 and $26,313 for the year ended December 31, 2023 and 2022, respectively (note 16)	281,508	205,217	144,895
Gross profit	276,215	183,615	114,856
Operating expenses:
Sales and marketing	47,019	39,889	26,733
Research and development	92,709	62,226	34,207
General and administrative	40,648	22,465	15,214
Total operating expenses	180,376	124,580	76,154
Income from operations	95,839	59,035	38,702
Interest income	8,354	8,740	505
Interest expense	(2,681)	(1,655)	(765)
Realized gain from sale of short-term investments	9,047	1,116	0
Unrealized gain (loss) on short-term investments	(2,737)	(7,855)	607
Other income (expense), net	(1,558)	3,315	(631)
Income from equity method investments	9,952	4,666	4,637
Income before income taxes	116,216	67,362	43,055
Income tax expense (note 19)	(19,364)	(16,798)	(134)
Net income	96,852	50,564	42,921
Less: Net income attributable to non-controlling interests	19,503	11,301	5,164
Net income attributable to ACM Research, Inc.	77,349	39,263	37,757
Comprehensive income (loss):
Net income	96,852	50,564	42,921
Foreign currency translation adjustment, net of tax	(10,617)	(59,102)	4,695
Comprehensive income (loss)	86,235	(8,538)	47,616
Less: Comprehensive income attributable to non-controlling interests	17,689	1,854	5,607
Comprehensive income (loss) attributable to ACM Research, Inc.	$ 68,546	$ (10,392)	$ 42,009
Net income per common stock (note 2):
Basic (in dollars per share)	$ 1.29	$ 0.66	$ 0.65
Diluted (in dollars per share)	$ 1.16	$ 0.59	$ 0.58
Weighted average common stock outstanding used in computing per share amounts (note 2):
Basic (in shares)	60,164,670	59,235,975	57,654,708
Diluted (in shares)	64,870,543	65,341,771	65,356,716

PARENT COMPANY ONLY CONDENSED FINANCIAL INFORMATION (Tables)

12 Months Ended

Dec. 31, 2023

Condensed Financial Information Disclosure [Abstract]

Condensed Balance Sheets

The following represents condensed unconsolidated financial information of ACM only as of December 31, 2023 and 2022, and for the years ended December 31, 2023, 2022 and 2021:

CONDENSED BALANCE SHEETS


	December 31,
	2023		2022
Assets
Current assets:
Cash and cash equivalents	$	41,616	$	23,853
Accounts receivable	988		24
Due from intercompany	3,176		-
Other receivable	5,803		5,017
Prepaid expenses	385		134
Total current assets	51,968		29,028
Deferred tax assets	20,271		6,703
Property, plant and equipment, net	134		-
Investment in consolidated subsidiaries and equity method investee	733,382		653,926
Total assets	$	805,755	$	689,657

Liabilities and Stockholders’ Equity
Loan borrowings	$	14,120	$	—
Accounts payable	524		$	236
Other payables	5,176		4,409
Income taxes payable	6,402		3,469
FIN-48 payable	12,149		6,686
Total liabilities	38,371		14,800
Total stockholders’ equity	767,384		674,857
Total liabilities and stockholder’s equity	$	805,755	$	689,657

Condensed Statements of Operations

CONDENSED STATEMENTS OF OPERATIONS


	Year Ended December 31,
	2023		2022		2021
Revenue	$	6,354	$	569	$	16
Cost of revenue	(4,336)		-		—
Gross profit	2,018		569		16
Operating expenses:
Sales and marketing expenses	(4,715)		(3,193)		(2,443)
General and administrative expenses	(7,840)		(5,421)		(5,116)
Loss from operations	(10,537)		(8,045)		(7,543)
Equity in earnings of consolidated subsidiaries and equity method investees	73,707		32,145		43,866
Interest income, net	799		57		54
Interest expense, net	(66)		(7)		-
Other income, net	18,476		2,148		1,380
Income before income taxes	82,379		26,298		37,757
Income tax benefit	(5,030)		12,965		-
Net income	$	77,349	$	39,263	$	37,757

Condensed Statements of Cash Flows

CONDENSED STATEMENTS OF CASH FLOWS


	Year Ended December 31,
	2023		2022		2021
Net cash provided by (used in) operating activities	$	1,489	$	(5,997)	$	(5,902)
Net cash used in investing activities	(149)		(1,000)		-
Net cash provided by financing activities	16,423		1,314		5,250
Net increase (decrease) in cash and cash equivalents	17,763		(5,683)		(652)
Cash and cash equivalents, beginning of year	23,853		29,536		30,188
Cash and cash equivalents, end of year	$	41,616	$	23,853	$	29,536

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 182,090	$ 247,951
Restricted cash	1,083	500
Short-term time deposits	80,524	70,492
Short-term investments	21,312	20,209
Accounts receivable, net	283,186	182,936
Prepaid expenses	20,023	15,607
Total current assets	1,176,110	963,806
Property, plant and equipment, net	201,848	82,875
Land use right, net	8,367	8,692
Operating lease right-of-use asset, net	7,026	2,489
Intangible assets, net	2,538	1,255
Long-term time deposits	40,818	101,956
Deferred tax assets	20,271	6,703
Long-term investments	27,880	17,459
Other long-term assets	6,050	50,265
Total assets	1,490,908	1,235,500
Current liabilities:
Short-term borrowings	31,335	56,004
Long-Term Debt, Current Maturities	6,783	2,322
Advances from customers	181,368	153,773
Deferred revenue	3,687	4,174
Income taxes payable	6,401	3,469
FIN-48 payable	12,149	6,686
Other payables and accrued expenses	102,951	52,201
Current portion of operating lease liability	2,764	1,382
Total current liabilities	500,659	396,214
Long-Term borrowings	53,952	18,687
Operating Lease, Liability, Noncurrent	4,262	1,107
Other Liabilities, Noncurrent	5,873	7,321
Total liabilities	564,746	423,329
Commitments and Contingencies
Equity:
Additional paid-in capital	629,845	604,089
Retained earnings	156,827	94,426
Statutory surplus revenue	30,060	16,881
Accumulated other comprehensive loss	(49,349)	(40,546)
Total ACM Research, Inc. stockholders’ equity	767,390	674,856
Non-controlling interests	158,772	137,315
Total equity	926,162	812,171
Total liabilities and equity	1,490,908	1,235,500
Nonrelated Party
Current assets:
Other receivables	40,065	29,617
Current liabilities:
Accounts payable	141,814	101,735
Related Party
Current assets:
Other receivables	2,432	3,322
Inventory, net	545,395	393,172
Current liabilities:
Accounts payable	11,407	14,468
Class A Common Stock
Equity:
Common stock	6	5
Class B Common Stock
Equity:
Common stock	$ 1	$ 1

INVENTORIES

12 Months Ended

Dec. 31, 2023

Inventory Disclosure [Abstract]

INVENTORIES

At December 31, 2023 and 2022, inventory consisted of the following:


	December 31,
	2023		2022
Raw materials	$	235,062	$	167,135
Work-in-process	81,438		79,126
Finished goods	228,895		146,911
Total inventory	$	545,395	$	393,172

At December 31, 2023 and December 31, 2022, the value of finished goods inventory, which is comprised of first-tools at customer physical locations, for which customers were contractually obligated to take ownership upon acceptance, totaled $123,390 and $123,169, respectively.

The $70,239 increase in raw materials and work-in-process inventory at December 31, 2023 compared to December 31, 2022 was due to additional purchase of supplies to support a higher level of expected total shipments for the next several quarters, and to reduce the risk of supply chain delays to meet anticipated customer demand for the Company’s products. The $81,984 increase in finished goods inventory at December 31, 2023 compared to December 31, 2022 reflects a higher value of completed tools at the Company's facilities, and a higher value of first-tools under evaluation by existing or prospective customers, due to shipments made, net of customer acceptances during the period.

The Company’s products each require a certain degree of customization, and the substantial majority of the work-in-process inventory and finished goods inventory is built to meet a specific customer order for repeat shipment or first tool delivery. At the end of each period, the Company assesses the status of each item in work-in-process and finished goods inventory. The Company recognizes a loss or impairment if in management’s judgement the inventory cannot be sold or used for production, if it has been damaged or should be considered as obsolete, or if the net realizable value is lower than the cost.

At the end of each period, the Company also assesses the status of its raw materials. The Company recognizes a loss or impairment for any raw materials aged more than three years. The three-year aging is based on the Company’s assessment of technology change, its requirement to maintain stock for warranty coverage, and other factors.

During the years ended December 31, 2023, 2022, and 2021, provision for inventory of $575, $2,248, and $75 were recognized in cost of revenue, respectively. Write-downs were due to an internal assessment that certain inventory could not be sold or used for production due to damage or obsolescence.

OTHER LONG-TERM LIABILITIES

12 Months Ended

Dec. 31, 2023

Other Liabilities Disclosure [Abstract]

OTHER LONG-TERM LIABILITIES


	December 31,
	2023		2022
Subsidies to Stress Free Polishing project, commenced in 2008 and 2017	$	475	$	611
Subsidies to other cleaning tools, commenced in 2020	632		785
Subsidies to SW Lingang R&D development in 2021	3,467		4,266
Subsidies to CO2 Technology	275		965
Other	1,024		694
Total	$	5,873	$	7,321

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Basic and Diluted Net Income per Common Share (Details) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2023 USD ($) class $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares
Numerator [Abstract]
Net income		$ 96,852	$ 50,564	$ 42,921
Less: Net income attributable to non-controlling interests		19,503	11,301	5,164
Net income available to common stockholders, basic		77,349	39,263	37,757
Less: Dilutive effect arising from stock-based awards by ACM Shanghai		1,841	584	108
Net income available to common stockholders, diluted		$ 75,508	$ 38,679	$ 37,649
Weighted average shares outstanding, basic (in shares) \| shares		60,164,670	59,235,975	57,654,708
Effect of dilutive securities (in shares) \| shares		4,705,873	6,105,796	7,702,008
Weighted average shares outstanding, diluted (in shares) \| shares		64,870,543	65,341,771	65,356,716
Net income per share of common stock:
Basic (in dollars per share) \| $ / shares		$ 1.29	$ 0.66	$ 0.65
Diluted (in dollars per share) \| $ / shares		$ 1.16	$ 0.59	$ 0.58
Stock split ratio	3
Antidilutive securities excluded from computation of earnings per share, amount \| shares		3,651,337	1,795,340	98,800
Classes of common stock outstanding \| class		2

SEGMENT INFORMATION (Details) $ in Thousands	12 Months Ended
SEGMENT INFORMATION (Details) $ in Thousands	Dec. 31, 2023 USD ($) segment	Dec. 31, 2022 USD ($)
Segment Reporting [Abstract]
Number of reporting segments \| segment	1
Geographic Areas, Long-Lived Assets [Abstract]
Long-lived assets	$ 223,191	$ 144,321
Mainland China
Geographic Areas, Long-Lived Assets [Abstract]
Long-lived assets	209,725	140,481
Korea
Geographic Areas, Long-Lived Assets [Abstract]
Long-lived assets	12,190	3,830
United States
Geographic Areas, Long-Lived Assets [Abstract]
Long-lived assets	$ 1,276	$ 10

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
Document and Entity Information - USD ($) $ in Millions	Dec. 31, 2023	Feb. 23, 2024	Jun. 30, 2023
Document Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2023
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-38273
Entity Registrant Name	ACM Research, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	94-3290283
Entity Address, Address Line One	42307 Osgood Road, Suite I
Entity Address, City or Town	Fremont
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94539
City Area Code	510
Local Phone Number	445-3700
Title of 12(b) Security	Class A Common Stock, $0.0001 par value
Trading Symbol	ACMR
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction	false
Entity Shell Company	false
Entity Public Float			$ 637.4
Entity Central Index Key	0001680062
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Amendment Flag	false
Class A Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		56,073,205
Class B Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		5,021,811

INCOME TAXES - Summary of Income Before Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
U.S. federal	$ 10,420	$ (3,456)	$ (4,389)
Foreign	105,796	70,818	47,444
Income before income taxes	$ 116,216	$ 67,362	$ 43,055

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Revenue Recognition (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Revenue Recognition and Deferred Revenue [Abstract]
Deferred revenue	$ 3,687	$ 4,174

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Statutory Surplus Reserve (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Retained Earnings (Accumulated Deficit) [Abstract]
Statutory surplus revenue	$ 30,060	$ 16,881
ACM Research (Shanghai), Inc.
Retained Earnings (Accumulated Deficit) [Abstract]
Statutory surplus revenue	$ 30,060

OTHER PAYABLES AND ACCRUED EXPENSES (Tables)

12 Months Ended

Dec. 31, 2023

Payables and Accruals [Abstract]

Other Payables and Accrued Expenses

At December 31, 2023 and 2022, other payables and accrued expenses consisted of the following:


	December 31,
	2023		2022
Accrued commissions	$	15,572	$	14,890
Accrued warranty	9,834		8,780
Accrued payroll	14,840		12,201
Accrued professional fees	696		724
Accrued machine testing fees	1,762		1,215
Accrued machine sales fees	6,010		5,874
Accrued Lingang construction fees	33,729		738
Others	20,508		7,779
Total	$	102,951	$	52,201

LAND USE RIGHT, NET (Details) - USD ($) $ in Thousands	12 Months Ended
LAND USE RIGHT, NET (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Land use Right [Abstract]
Land use right purchase amount	$ 8,996	$ 9,149
Less: accumulated amortization	(629)	(457)
Land use right, net	$ 8,367	8,692
Right to use land lease term	50 years
Amortization	$ 181	189	$ 199
Annual Amortization of Land use Right [Abstract]
2024	180
2025	180
2026	180
2027	180
2028	180
2029 and thereafter	7,467
Land use right, net	$ 8,367	$ 8,692

LONG-TERM BORROWINGS - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) installment loan	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Line of Credit Facility [Line Items]
Long-term debt	$ 60,735	$ 21,009
Long-term borrowings	56,462	18,538
Interest costs incurred	$ 1,100	845	$ 1,040
Interest expense, long-term debt			65
Capitalized interest charged as other long-term assets			$ 975
China Merchants Bank
Line of Credit Facility [Line Items]
Number of installments for loan repayable \| installment	120
Interest rate during period	4.65%
Long-term debt	$ 13,362	15,265
Bank of China
Line of Credit Facility [Line Items]
Number of loans \| loan	2
Long-term debt	$ 5,013	5,744
Bank of China \| Loan 1
Line of Credit Facility [Line Items]
Number of installments for loan repayable \| installment	6
Interest rate during period	2.60%
Bank of China \| Loan 2
Line of Credit Facility [Line Items]
Number of installments for loan repayable \| installment	6
Interest rate during period	2.60%
Bank of Shanghai
Line of Credit Facility [Line Items]
Interest rate during period	2.85%
Long-term debt	$ 14,120	0
CITIC Bank
Line of Credit Facility [Line Items]
Long-term debt	$ 28,240	$ 0
CITIC Bank \| Loan 1
Line of Credit Facility [Line Items]
Number of installments for loan repayable \| installment	4
Interest rate during period	3.40%
CITIC Bank \| Loan 2
Line of Credit Facility [Line Items]
Number of installments for loan repayable \| installment	4
Interest rate during period	4.50%

PARENT COMPANY ONLY CONDENSED FINANCIAL INFORMATION

12 Months Ended

Dec. 31, 2023

Condensed Financial Information Disclosure [Abstract]

PARENT COMPANY ONLY CONDENSED FINANCIAL INFORMATION

The Company performed a test on the restricted net assets of consolidated subsidiaries in accordance with Rule 4-08(e)(3) of Regulation S-X of the SEC and concluded that it was applicable for the Company to disclose the financial information

for ACM only. Certain information and footnote disclosures generally included in financial statements prepared in accordance with GAAP have been condensed or omitted. The footnote disclosure contains supplemental information relating to the operations of ACM separately.

ACM Shanghai paid a dividend to ACM during the year ended December 31, 2023 (Note 2).

Except for long-term obligations, or guarantees, and loan borrowed by ACM Inc. from CITIC. (note 12), ACM does not have significant capital or other commitments, as of December 31, 2023 or 2022.

The following represents condensed unconsolidated financial information of ACM only as of December 31, 2023 and 2022, and for the years ended December 31, 2023, 2022 and 2021:

CONDENSED BALANCE SHEETS


	December 31,
	2023		2022
Assets
Current assets:
Cash and cash equivalents	$	41,616	$	23,853
Accounts receivable	988		24
Due from intercompany	3,176		-
Other receivable	5,803		5,017
Prepaid expenses	385		134
Total current assets	51,968		29,028
Deferred tax assets	20,271		6,703
Property, plant and equipment, net	134		-
Investment in consolidated subsidiaries and equity method investee	733,382		653,926
Total assets	$	805,755	$	689,657

Liabilities and Stockholders’ Equity
Loan borrowings	$	14,120	$	—
Accounts payable	524		$	236
Other payables	5,176		4,409
Income taxes payable	6,402		3,469
FIN-48 payable	12,149		6,686
Total liabilities	38,371		14,800
Total stockholders’ equity	767,384		674,857
Total liabilities and stockholder’s equity	$	805,755	$	689,657

CONDENSED STATEMENTS OF OPERATIONS


	Year Ended December 31,
	2023		2022		2021
Revenue	$	6,354	$	569	$	16
Cost of revenue	(4,336)		-		—
Gross profit	2,018		569		16
Operating expenses:
Sales and marketing expenses	(4,715)		(3,193)		(2,443)
General and administrative expenses	(7,840)		(5,421)		(5,116)
Loss from operations	(10,537)		(8,045)		(7,543)
Equity in earnings of consolidated subsidiaries and equity method investees	73,707		32,145		43,866
Interest income, net	799		57		54
Interest expense, net	(66)		(7)		-
Other income, net	18,476		2,148		1,380
Income before income taxes	82,379		26,298		37,757
Income tax benefit	(5,030)		12,965		-
Net income	$	77,349	$	39,263	$	37,757

CONDENSED STATEMENTS OF CASH FLOWS


	Year Ended December 31,
	2023		2022		2021
Net cash provided by (used in) operating activities	$	1,489	$	(5,997)	$	(5,902)
Net cash used in investing activities	(149)		(1,000)		-
Net cash provided by financing activities	16,423		1,314		5,250
Net increase (decrease) in cash and cash equivalents	17,763		(5,683)		(652)
Cash and cash equivalents, beginning of year	23,853		29,536		30,188
Cash and cash equivalents, end of year	$	41,616	$	23,853	$	29,536

INCOME TAXES - Summary of Gross Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Aggregate Changes in Balance of Gross Unrecognized Tax Benefits [Abstract]
Beginning balance	$ 8,448	$ 6,066	$ 570
Increase of unrecognized tax benefits taken in prior years	199	0	52
Increase of unrecognized tax benefits related to current year	4,379	2,623	5,476
Reductions for tax positions related to prior years	0	(241)	(32)
Ending balance	$ 13,026	$ 8,448	$ 6,066

PROPERTY, PLANT AND EQUIPMENT, NET (Tables)

12 Months Ended

Dec. 31, 2023

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

At December 31, 2023 and 2022, property, plant and equipment consisted of the following:


	December 31,
	2023		2022
Buildings and plants	$	83,109	$	35,864
Manufacturing equipment	16,556		9,298
Office equipment	4,953		3,691
Transportation equipment	404		407
Leasehold improvement	7,889		7,173
Total cost	112,911		56,433
Less: Total accumulated depreciation and amortization	(17,503)		(10,047)
Construction in progress	106,440		36,489
Total property, plant and equipment, net	$	201,848	$	82,875

LONG-TERM BORROWINGS (Tables)

12 Months Ended

Dec. 31, 2023

Long-Term Debt, by Current and Noncurrent [Abstract]

Long-Term Borrowings

At December 31, 2023 and 2022, long-term borrowings consisted of the following:


	December 31,
	2023		2022
Loan from China Merchants Bank	$	13,362	$	15,265
Loans from Bank of China	5,013		5,744
Loan from Bank of Shanghai	14,120		—
Loans from China CITIC Bank	28,240		—
Less: Current portion	(6,783)		(2,322)
	$	53,952	$	18,687

Principal Payments for Outstanding Long-Term Loans

Scheduled principal payments for the outstanding long-term loans, including the current portion, as of December 31, 2023 are as follows:


Year ending December 31,
2024	$	6,783
2025	44,087
2026	1,855
2027	1,929
2028	2,007
Thereafter	4,074
	$	60,735

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

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+ Details

INCOME TAXES - Summary of Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets:
Net operating loss carry forwards (offshore)	$ 11,499	$ 1,456
Net operating loss carry forwards (U.S.) and credit	4,930	1,246
Deferred revenue (offshore)	2,277	1,826
Accruals (U.S.)	3,632	100
Reserves and other (offshore)	4,662	3,655
Stock-based compensation (U.S.)	2,455	2,060
Stock-based compensation (offshore)	4,393	1,229
Lease liability	1,252	414
Total gross deferred tax assets	35,100	11,986
Less: valuation allowance	(11,917)	(1,782)
Total deferred tax assets	23,183	10,204
Deferred tax liabilities:
Fixed assets	(1,325)	(443)
Equity Investments and unrealized gain on short-term investments	(1,587)	(3,059)
Total deferred tax liabilities	(2,912)	(3,502)
Deferred tax assets, net	$ 20,271	$ 6,702

DESCRIPTION OF BUSINESS (Tables)

12 Months Ended

Dec. 31, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Direct or Indirect Interests of Subsidiaries

The Company has direct or indirect interests in the following subsidiaries:


	Place and date of incorporation	Effective interest held as at December 31,
Name of subsidiaries		2023	2022
ACM Research (Shanghai), Inc.	Mainland China, May 2005	82.1%	82.5%
ACM Research (Wuxi), Inc.	Mainland China, July 2011	82.1%	82.5%
CleanChip Technologies Limited	Hong Kong, June 2017	82.1%	82.5%
ACM Research Korea CO., LTD.	Korea, December 2017	82.1%	82.5%
ACM Research (Lingang), Inc. (1)	Mainland China, March 2019	82.1%	82.5%
ACM Research (CA), Inc.	USA, April 2019	82.1%	82.5%
ACM Research (Cayman), Inc.	Cayman Islands, April 2019	100.0%	100.0%
ACM Research (Singapore) PTE. Ltd.	Singapore, August 2021	100.0%	100.0%
ACM Research (Beijing), Inc.	Mainland China, February 2022	82.1%	82.5%
Hanguk ACM CO., LTD	Korea, March 2022	100.0%	100.0%
Yusheng Micro Semiconductor (Shanghai) Co., Ltd.	Mainland China, June 2023	82.1%	-
ACM-Wooil Microelectronics (Shanghai) Co., Ltd.	Mainland China, June 2023	59.4%	-

LONG-TERM INVESTMENTS (Tables)

12 Months Ended

Dec. 31, 2023

Long-Term Investments [Abstract]

Long-Term Investments


	December 31,
Equity investee:	2023		2022
Ninebell	$	5,632	$	5,199
Wooil	1,003		1,011
Shengyi	1,693		1,168
Hefei Shixi	9,174		8,645
Subtotal	17,502		16,023
Investments accounted for using measurement alternative:
Waferworks	1,412		1,436
Shengyi	857		—
Company A	4,236		—
Company B	932		—
Other	2,941		—
Total	$	27,880	$	17,459

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Accounts Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Accounts Receivable [Abstract]
Allowance for credit loss	$ 4,830	$ 0

SHORT-TERM BORROWINGS

12 Months Ended

Dec. 31, 2023

Debt Disclosure [Abstract]

SHORT-TERM BORROWINGS

At December 31, 2023 and December 31, 2022, short-term borrowings consisted of the following:


	December 31,
	2023	2022
Line of credit up to RMB 150,000 from China Everbright Bank,
1)due on August 17, 2023 with an annual interest rate of 3.40%.	—	8,616
2)due on September 1, 2023 with an annual interest rate of 3.60%.	—	8,616


3)due on December 16, 2023 with an annual interest rate of 3.00%	-	4,308
4)due on August 29,2024 with an annual interest rate of 3.00%.	2,463	-
Line of credit up to RMB 100,000 from Bank of Communications,
1)due on August 11, 2023 with an annual interest rate of 3.60%.	—	8,616
2)due on September 5, 2023 with an annual interest rate of 3.50%.	—	5,744
Line of credit up to RMB 40,000 from Bank of China,
1)due on August 26, 2023 with an annual interest rate of 3.15%.	—	5,744
Line of credit up to RMB 40,000 from Bank of China,
1)due on September 7, 2024 with an annual interest rate of 2.87%	5,648	—
Line of credit up to RMB 100,000 from China Merchants Bank,
1)due on July 21, 2023 with an annual interest rate of 3.50%	—	1,292
2)due on July 27, 2023 with an annual interest rate of 3.50%	—	1,292
3)due on August 1, 2023 with an annual interest rate of 3.50%	—	1,292
4)due on August 3, 2023 with an annual interest rate of 3.50%	—	1,292
5)due on August 7, 2023 with an annual interest rate of 3.50%	—	1,293
6)due on August 14, 2023 with an annual interest rate of 3.50%	—	1,293
7)due on August 15, 2023 with an annual interest rate of 3.50%	—	1,293
8)due on August 21, 2023 with an annual interest rate of 3.50%	—	1,005
9)due on August 28, 2023 with an annual interest rate of 3.50%	—	1,292
10)due on September 13, 2023 with an annual interest rate of 3.50%	—	1,292
11)due on September 20, 2023 with an annual interest rate of 3.50%	—	1,293
12)due on October 7, 2023 with an annual interest rate of 3.50%	—	431
Line of credit up to RMB 200,000 from China Merchants Bank,
1)due on August 7,2024 with an annual interest rate of 3.00%.	1,271	-
2)due on August 8,2024 with an annual interest rate of 3.00%.	1,271	-
3)due on August 9,2024 with an annual interest rate of 3.00%.	1,271	-
4)due on August 14,2024 with an annual interest rate of 3.00%.	1,271	-
5)due on August 17,2024 with an annual interest rate of 3.00%.	1,271	-
6)due on August 20,2024 with an annual interest rate of 3.00%.	1,271	-
7)due on August 21,2024 with an annual interest rate of 3.00%.	1,271	-
8)due on August 22,2024 with an annual interest rate of 3.00%.	1,271	-
9)due on August 24,2024 with an annual interest rate of 3.00%.	1,271	-
10)due on August 27,2024 with an annual interest rate of 3.00%.	1,271	-
11)due on August 29,2024 with an annual interest rate of 3.00%.	1,271	-
12)due on August 30,2024 with an annual interest rate of 3.00%.	1,271	-
13)due on September 3,2024 with an annual interest rate of 3.00%.	1,271	-
14)due on September 5,2024 with an annual interest rate of 3.00%.	1,270	-
15)due on September 6,2024 with an annual interest rate of 3.00%.	1,270	-
16)due on September 10,2024 with an annual interest rate of 3.00%.	1,270	-
17)due on September 12,2024 with an annual interest rate of 3.00%.	1,270	-
Line of credit up to KRW 500,000 from Industrial Bank of Korea,
1)due on July 12,2024 with an annual interest rate of 6.03%.	77	-
Line of credit up to KRW 2,000,000 from Industrial Bank of Korea,


1)due on December 15,2024 with an annual interest rate of 4.27%.	1,544		-
Total	$	31,335	$	56,004

For the years ended December 31, 2023, 2022 and 2021, interest expense related to short-term borrowings amounted to $1,581, $810, and $700, respectively.

Pay vs Performance Disclosure - USD ($) $ in Thousands	12 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pay vs Performance Disclosure
Net income attributable to ACM Research, Inc.	$ 77,349	$ 39,263	$ 37,757

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 60B
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-60B

Reference 32: http://www.xbrl.org/2003/role/exampleRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 31
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-31

Reference 33: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Topic 205
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Publisher FASB
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Reference 35: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 230
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-Paragraph 28
-Publisher FASB
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Reference 36: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1A
-Subparagraph (a)
-Publisher FASB
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Reference 37: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
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-Name Accounting Standards Codification
-Section 45
-Paragraph 1B
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482790/220-10-45-1B

Reference 38: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(20))
-Publisher FASB
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Reference 39: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
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-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(22))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1

+ Details

DESCRIPTION OF BUSINESS - Summary Of Subsidiaries (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
ACM Research (Shanghai), Inc.
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Place and date of incorporation	Mainland China, May 2005
Effective interest held	82.10%	82.50%
ACM Research (Wuxi), Inc.
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Place and date of incorporation	Mainland China, July 2011
Effective interest held	82.10%	82.50%
CleanChip Technologies Limited
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Place and date of incorporation	Hong Kong, June 2017
Effective interest held	82.10%	82.50%
ACM Research Korea CO., LTD.
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Place and date of incorporation	Korea, December 2017
Effective interest held	82.10%	82.50%
ACM Research (Lingang), Inc. (1)
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Place and date of incorporation	Mainland China, March 2019
Effective interest held	82.10%	82.50%
ACM Research (CA), Inc.
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Place and date of incorporation	USA, April 2019
Effective interest held	82.10%	82.50%
ACM Research (Cayman), Inc.
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Place and date of incorporation	Cayman Islands, April 2019
Effective interest held	100.00%	100.00%
ACM Research (Singapore) PTE. Ltd.
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Place and date of incorporation	Singapore, August 2021
Effective interest held	100.00%	100.00%
ACM Research (Beijing), Inc.
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Place and date of incorporation	Mainland China, February 2022
Effective interest held	82.10%	82.50%
Hanguk ACM CO., LTD
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Place and date of incorporation	Korea, March 2022
Effective interest held	100.00%	100.00%
Yusheng Micro Semiconductor (Shanghai) Co., Ltd.
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Place and date of incorporation	Mainland China, June 2023
Effective interest held	82.10%	0.00%
ACM-Wooil Microelectronics (Shanghai) Co., Ltd.
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Place and date of incorporation	Mainland China, June 2023
Effective interest held	59.40%	0.00%

SHORT-TERM BORROWINGS (Details) ₩ in Thousands, ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2023 CNY (¥)	Dec. 31, 2023 KRW (₩)	Dec. 31, 2022 CNY (¥)
Short-Term and Long-term Borrowings [Abstract]
Short-term borrowings	$ 31,335	$ 56,004
Interest expense related to short-term borrowings	$ 1,581	$ 810	$ 700
Line of credit up to RMB 150,000 from China Everbright Bank,
Short-Term and Long-term Borrowings [Abstract]
Maximum borrowing capacity \| ¥				¥ 150,000		¥ 150,000
Line of Credit Due On August 17, 2023 With An Annual Interest Rate Of 3.40%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.40%	3.40%
Short-term borrowings	$ 0	$ 8,616
Line of Credit Due On September 1, 2023 With An Annual Interest Rate Of 3.60%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.60%	3.60%
Short-term borrowings	$ 0	$ 8,616
Line of Credit Due On December 16, 2023 With An Annual Interest Rate Of 3.00%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.00%	3.00%
Short-term borrowings	$ 0	$ 4,308
Line of Credit Due On August 29, 2024 With An Annual Interest Rate Of 3.00%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.00%
Short-term borrowings	$ 2,463	$ 0
Line of credit up to RMB 100,000 from Bank of Communications,
Short-Term and Long-term Borrowings [Abstract]
Maximum borrowing capacity \| ¥				100,000		100,000
Line Of Credit, Due On August 11, 2023 With An Annual Interest Rate Of 3.60%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.60%	3.60%
Short-term borrowings	$ 0	$ 8,616
Line Of Credit, Due On September 5, 2023 With An Annual Interest Rate Of 3.50%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.50%	3.50%
Short-term borrowings	$ 0	$ 5,744
Line of credit up to RMB 40,000 from Bank of China,
Short-Term and Long-term Borrowings [Abstract]
Maximum borrowing capacity \| ¥				40,000		40,000
Line Of Credit, Due On August 26, 2023 With An Annual Interest Rate Of 3.15%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.15%	3.15%
Short-term borrowings	$ 0	$ 5,744
Line of credit up to RMB 40,000 from Bank of China,
Short-Term and Long-term Borrowings [Abstract]
Maximum borrowing capacity \| ¥				40,000
Line of Credit, China Merchants Bank, due on September 7, 2024 with an annual interest rate of 2.87%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	2.87%
Short-term borrowings \| ¥				5,648		0
Line of credit up to RMB 100,000 from China Merchants Bank,
Short-Term and Long-term Borrowings [Abstract]
Maximum borrowing capacity \| ¥				100,000		100,000
Line Of Credit, Due On July 21, 2023 With An Annual Interest Rate Of 3.50%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.50%	3.50%
Short-term borrowings	$ 0	$ 1,292
Line Of Credit, Due On July 27, 2023 With An Annual Interest Rate Of 3.50%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.50%	3.50%
Short-term borrowings	$ 0	$ 1,292
Line Of Credit, Due On August 1, 2023 With An Annual Interest Rate Of 3.50%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.50%	3.50%
Short-term borrowings	$ 0	$ 1,292
Line Of Credit, Due On August 3, 2023 With An Annual Interest Rate Of 3.50%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.50%	3.50%
Short-term borrowings	$ 0	$ 1,292
Line Of Credit, Due On August 7, 2023 With An Annual Interest Rate Of 3.50%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.50%	3.50%
Short-term borrowings	$ 0	$ 1,293
Line Of Credit, Due On August 14, 2023 With An Annual Interest Rate Of 3.50%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.50%	3.50%
Short-term borrowings	$ 0	$ 1,293
Line Of Credit, Due On August 15, 2023 With An Annual Interest Rate Of 3.50%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.50%	3.50%
Short-term borrowings	$ 0	$ 1,293
Line Of Credit, Due On August 21, 2023 With An Annual Interest Rate Of 3.50%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.50%	3.50%
Short-term borrowings	$ 0	$ 1,005
Line Of Credit, Due On August 28, 2023 With An Annual Interest Rate Of 3.50%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.50%	3.50%
Short-term borrowings	$ 0	$ 1,292
Line Of Credit, Due On September 13, 2023 With An Annual Interest Rate Of 3.50%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.50%	3.50%
Short-term borrowings	$ 0	$ 1,292
Line Of Credit, Due On September 20, 2023 With An Annual Interest Rate Of 3.50%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.50%	3.50%
Short-term borrowings	$ 0	$ 1,293
Line Of Credit, Due On September 29, 2023 With An Annual Interest Rate Of 3.50%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.50%	3.50%
Short-term borrowings	$ 0	$ 431
Line of credit up to RMB 200,000 from China Merchants Bank,
Short-Term and Long-term Borrowings [Abstract]
Maximum borrowing capacity \| ¥				¥ 200,000		¥ 200,000
Line of Credit, China Merchants Bank, due on August 7, 2024 with an annual interest rate of 3.00%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.00%
Short-term borrowings	$ 1,271	0
Line of Credit, China Merchants Bank, due on August 8, 2024 with an annual interest rate of 3.00%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.00%
Short-term borrowings	$ 1,271	0
Line of Credit, China Merchants Bank, due on August 9, 2024 with an annual interest rate of 3.00%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.00%
Short-term borrowings	$ 1,271	0
Line of Credit, China Merchants Bank, due on August 14, 2024 with an annual interest rate of 3.00%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.00%
Short-term borrowings	$ 1,271	0
Line of Credit, China Merchants Bank, due on August 17, 2024 with an annual interest rate of 3.00%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.00%
Short-term borrowings	$ 1,271	0
Line of Credit, China Merchants Bank, due on August 20, 2024 with an annual interest rate of 3.00%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.00%
Short-term borrowings	$ 1,271	0
Line of Credit, China Merchants Bank, due on August 21, 2024 with an annual interest rate of 3.00%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.00%
Short-term borrowings	$ 1,271	0
Line of Credit, China Merchants Bank, due on August 22, 2024 with an annual interest rate of 3.00%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.00%
Short-term borrowings	$ 1,271	0
Line of Credit, China Merchants Bank, due on August 24, 2024 with an annual interest rate of 3.00%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.00%
Short-term borrowings	$ 1,271	0
Line of Credit, China Merchants Bank, due on August 27, 2024 with an annual interest rate of 3.00%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.00%
Short-term borrowings	$ 1,271	0
Line of Credit, China Merchants Bank, due on August 29, 2024 with an annual interest rate of 3.00%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.00%
Short-term borrowings	$ 1,271	0
Line of Credit, China Merchants Bank, due on August 30, 2024 with an annual interest rate of 3.00%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.00%
Short-term borrowings	$ 1,271	0
Line of Credit, China Merchants Bank, due on September 3, 2024 with an annual interest rate of 3.00%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.00%
Short-term borrowings	$ 1,271	0
Line of Credit, China Merchants Bank, due on September 5, 2024 with an annual interest rate of 3.00%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.00%
Short-term borrowings	$ 1,270	0
Line of Credit, China Merchants Bank, due on September 6, 2024 with an annual interest rate of 3.00%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.00%
Short-term borrowings	$ 1,270	0
Line of Credit, China Merchants Bank, due on September 10, 2024 with an annual interest rate of 3.00%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.00%
Short-term borrowings	$ 1,270	0
Line of Credit, China Merchants Bank, due on September 12, 2024 with an annual interest rate of 3.00%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	3.00%
Short-term borrowings	$ 1,270	0
Line of credit up to KRW 500,000 from Industrial Bank of Korea,
Short-Term and Long-term Borrowings [Abstract]
Maximum borrowing capacity \| ₩					₩ 500,000
Line of Credit Due On July 12, 2024 With An Annual Interest Rate Of 6.03%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	6.03%
Short-term borrowings	$ 77	0
Line of credit up to KRW 2,000,000 from Industrial Bank of Korea,
Short-Term and Long-term Borrowings [Abstract]
Maximum borrowing capacity \| ₩					₩ 2,000,000
Line of Credit Due On December 15, 2024 With An Annual Interest Rate Of 4.29%
Short-Term and Long-term Borrowings [Abstract]
Interest rate during period	4.27%
Short-term borrowings	$ 1,544	$ 0

PROPERTY, PLANT AND EQUIPMENT, NET

12 Months Ended

Dec. 31, 2023

Property, Plant and Equipment [Abstract]

PROPERTY, PLANT AND EQUIPMENT, NET

At December 31, 2023 and 2022, property, plant and equipment consisted of the following:


	December 31,
	2023		2022
Buildings and plants	$	83,109	$	35,864
Manufacturing equipment	16,556		9,298
Office equipment	4,953		3,691
Transportation equipment	404		407
Leasehold improvement	7,889		7,173
Total cost	112,911		56,433
Less: Total accumulated depreciation and amortization	(17,503)		(10,047)
Construction in progress	106,440		36,489
Total property, plant and equipment, net	$	201,848	$	82,875

Depreciation expense was $6,912, $4,839, and $2,099 for the years ended December 31, 2023, 2022, and 2021, respectively. Buildings and plants represent Lingang housing property owned by ACM Shengwei at a value of RMB 249,746 ($35,264) as of December 31, 2023, and facilities for the new headquarters of ACM Shanghai ("Zhangjiang New Building") at a value of RMB 338,848 ($47,845) as of December 31, 2023. The Lingang housing property is pledged as security for loans from China Merchants Bank (Note 12).

Construction in progress primarily reflects costs incurred related to the construction of ACM Shanghai’s Lingang development and production center, and is scheduled to begin production in 2024.

REVENUE FROM CONTRACTS WITH CUSTOMERS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disaggregated Revenue Information [Abstract]
Revenue	$ 557,723	$ 388,832	$ 259,751
Accounts Receivables and Contract Liabilities [Abstract]
Accounts receivable	283,186	182,936
Advances from customers	181,368	153,773
Deferred revenue	3,687	4,174
Advances from customers	29,974	104,258	34,831
Revenue recognized from amounts included in contract liabilities at the beginning of the year	97,370	30,385	13,425
First-Tools
Accounts Receivables and Contract Liabilities [Abstract]
Advances from customers	27,595
Mainland China
Disaggregated Revenue Information [Abstract]
Revenue	540,969	377,752	258,615
Other regions
Disaggregated Revenue Information [Abstract]
Revenue	16,754	11,080	1,136
Single Wafer Cleaning, Tahoe and Semi-Critical Cleaning Equipment
Disaggregated Revenue Information [Abstract]
Revenue	403,851	272,939	189,208
ECP (front-end and packaging), Furnace and Other Technologies
Disaggregated Revenue Information [Abstract]
Revenue	103,356	77,482	33,210
Advanced Packaging (excluding ECP), Services & Spares
Disaggregated Revenue Information [Abstract]
Revenue	$ 50,516	$ 38,411	$ 37,333

COMMON STOCK	12 Months Ended
COMMON STOCK	Dec. 31, 2023
Equity [Abstract]
COMMON STOCK	COMMON STOCK At December 31, 2023 and 2022, ACM was authorized to issue 150,000,000 shares of Class A common stock and 5,307,816 shares of Class B common stock, each with a par value of $0.0001. Each share of Class A common stock is entitled to one vote, and each share of Class B common stock is entitled to twenty votes and is convertible at any time into one share of Class A common stock. Shares of Class A common stock and Class B common stock are treated equally, identically and ratably with respect to any dividends declared by the Board of Directors unless the Board of Directors declares different dividends to the Class A common stock and Class B common stock by getting approval from a majority of common stockholders. During the year ended December 31, 2023, ACM issued 1,380,886 shares of Class A common stock upon option exercises by employees and non-employees. During the year ended December 31, 2022, ACM issued 980,354 shares of Class A common stock upon options exercises by certain employees and non-employees and an additional 66,003 shares of Class A common stock upon conversion of an equal number of shares of Class B common stock. At December 31, 2023 and 2022, the number of shares of Class A common stock issued and outstanding was 56,036,172 and 54,655,286, respectively. At December 31, 2023 and 2022, the number of shares of Class B common stock issued and outstanding was 5,021,811 and 5,021,811, respectively.

- Definition

The entire disclosure for equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (b)
-Publisher FASB
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
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-Name Accounting Standards Codification
-Section 50
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
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-Name Accounting Standards Codification
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
-Section S99
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
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-Paragraph 1
-Subparagraph (SX 210.4-08(e)(1))
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Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
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-URI https://asc.fasb.org//505/tableOfContent

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (i)
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-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
-Section 50
-Paragraph 14
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Reference 15: http://www.xbrl.org/2003/role/disclosureRef
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Reference 16: http://www.xbrl.org/2003/role/disclosureRef
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Reference 17: http://www.xbrl.org/2003/role/disclosureRef
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Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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Reference 19: http://www.xbrl.org/2003/role/disclosureRef
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-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-18

+ Details

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Time Deposits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Time Deposits [Abstract]
Time deposits	$ 121,342	$ 172,448
Interest income	$ 3,689	3,472
China Merchant Bank, Deposits, Maturing on January 29, 2023
Time Deposits [Abstract]
Time deposits, interest rate	2.25%
Time deposits	$ 0	38,772
China Everbright Bank, Deposit, Maturing on January 29, 2023
Time Deposits [Abstract]
Time deposits, interest rate	2.25%
Time deposits	$ 0	14,360
China Everbright Bank, Deposit, Maturing on May 22, 2023
Time Deposits [Abstract]
Time deposits, interest rate	5.07%
Time deposits	$ 0	3,000
China Industrial Bank, Deposit, Maturing on January 30, 2023
Time Deposits [Abstract]
Time deposits, interest rate	2.15%
Time deposits	$ 0	14,360
China Merchant Bank, Deposit, Maturing on January 29, 2024
Time Deposits [Abstract]
Time deposits, interest rate	2.85%
Time deposits	$ 29,797	28,720
Bank of Ningbo, Deposit, Maturing on February 17, 2024
Time Deposits [Abstract]
Time deposits, interest rate	2.85%
Time deposits	$ 44,630	43,080
Shanghai Pudong Development Bank, Deposit, Maturing on October 20, 2025
Time Deposits [Abstract]
Time deposits, interest rate	3.10%
Time deposits	$ 7,322	7,180
Shanghai Pudong Development Bank, Deposit, Maturing on November 14, 2025
Time Deposits [Abstract]
Time deposits, interest rate	3.10%
Time deposits	$ 7,307	7,180
Shanghai Pudong Development Bank, Deposit, Maturing on December 8, 2025
Time Deposits [Abstract]
Time deposits, interest rate	3.10%
Time deposits	$ 4,376	4,308
Shanghai Pudong Development Bank, Deposit, Maturing on December 15, 2025
Time Deposits [Abstract]
Time deposits, interest rate	3.10%
Time deposits	$ 4,373	4,308
Shanghai Pudong Development Bank, Deposit, Maturing on December 30, 2025
Time Deposits [Abstract]
Time deposits, interest rate	3.10%
Time deposits	$ 2,912	7,180
China Industrial Bank, Deposit, Maturing on January 30, 2026
Time Deposits [Abstract]
Time deposits, interest rate	3.15%
Time deposits	$ 14,528	0
China Everbright Bank, Deposit, Maturing on January 5, 2024
Time Deposits [Abstract]
Time deposits, interest rate	5.38%
Time deposits	$ 3,079	0
China Everbright Bank, Deposit, Maturing on May 22, 2024
Time Deposits [Abstract]
Time deposits, interest rate	5.38%
Time deposits	$ 3,018	$ 0

INCOME TAXES - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Taxes [Line Items]
Net operating loss carryforwards subject to annual limitation ownership change	$ 3,121
Amortization period (in years)	15 years
Foreign rate differential	(10.47%)	(9.43%)	(11.60%)
Accrued income tax penalties	$ 1,667	$ 508
Unrecognized tax benefits that would impact effective tax rate	12,943
Undistributed earnings of foreign subsidiaries	$ 130,000
ACM Research (Shanghai), Inc.
Income Taxes [Line Items]
Foreign rate differential	15.00%
U.S. Federal
Income Taxes [Line Items]
Valuation allowance	$ 29	49
Operating loss carryforwards	3,121	4,385
U.S. State
Income Taxes [Line Items]
Valuation allowance	279	277
Operating loss carryforwards	593	545
PRC
Income Taxes [Line Items]
Valuation allowance	11,585	1,456
Operating loss carryforwards	$ 46,467	$ 6,474
PRC \| Minimum
Income Taxes [Line Items]
Foreign corporate tax rate		12.50%	12.50%
PRC \| Maximum
Income Taxes [Line Items]
Foreign corporate tax rate	25.00%
PRC \| ACM Research (Shanghai), Inc.
Income Taxes [Line Items]
Foreign rate differential		12.50%
Foreign corporate tax rate	12.50%

ACCOUNTS RECEIVABLE (Tables)

12 Months Ended

Dec. 31, 2023

Receivables [Abstract]

Accounts Receivable

At December 31, 2023 and 2022, accounts receivable consisted of the following:


	December 31,
	2023		2022
Accounts receivable	$	288,016	$	182,936
Less: Allowance for credit losses	(4,830)		-
Total	$	283,186	$	182,936


	December 31,
	2023		2022
Cumulative effect of change in accounting principle under ASC 326, before tax, as of January 1, 2023	$	(2,099)	$	—
Provision for credit loss	(2,731)		—
Allowance for credit losses, before tax, as of December 31, 2023	$	(4,830)	$	—

RELATED PARTY BALANCES AND TRANSACTIONS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Related Party Transaction [Line Items]
Cost of revenue, including cost of revenue from related party of $31,240 and $26,313 for the year ended December 31, 2023 and 2022, respectively (note 16)	$ 281,508	$ 205,217	$ 144,895
Related Party
Related Party Transaction [Line Items]
Accounts payable	11,407	14,468
Purchase of materials	47,743	46,335	36,093
Cost of revenue, including cost of revenue from related party of $31,240 and $26,313 for the year ended December 31, 2023 and 2022, respectively (note 16)	31,240	26,313
Related Party \| Ninebell
Related Party Transaction [Line Items]
Advances to related party	2,432	3,322
Accounts payable	7,624	10,526
Purchase of materials	42,737	40,985	33,659
Related Party \| Shengyi
Related Party Transaction [Line Items]
Accounts payable	3,783	3,942
Purchase of materials	5,006	5,350	2,434
Cost of revenue, including cost of revenue from related party of $31,240 and $26,313 for the year ended December 31, 2023 and 2022, respectively (note 16)	$ 820	$ 543	$ 561

- Definition

The aggregate cost of goods produced and sold and services rendered during the reporting period.

+ References

+ Details

LEASES (Tables)

12 Months Ended

Dec. 31, 2023

Leases [Abstract]

Components of Lease Expense

The components of lease expense were as follows:


	Year Ended December 31,
	2023		2022		2021
Operating lease cost	$	3,580	$	2,816	$	2,451
Short-term lease cost	923		786		394
Lease cost	$	4,503	$	3,602	$	2,845

Supplemental Cash Flow Information Related to Operating Leases

Supplemental cash flow information related to operating leases was as follows for the years ended December 31, 2023, 2022, and 2021:


	Year Ended December 31,
	2023		2022		2021
Operating cash outflow from operating leases	$	3,580	$	2,816	$	2,451


Operating lease right-of-use assets obtained in exchange for new operating lease liabilities			$	8,195					$	1,054					$	1,818

Maturities of Outstanding Lease Liabilities for Operating Leases

Maturities of lease liabilities for all operating leases were as follows as of December 31, 2023:


	December 31,
2024	$	3,016
2025	1,767
2026	1,207
2027	1,150
2028 and thereafter	595
Total lease payments	$	7,735
Less: Interest	(709)
Present value of lease liabilities	$	7,026

Weighted Average Remaining Lease Terms and Discount Rates for Operating Leases

The weighted average remaining lease terms and discount rates for all operating leases were as follows as of December 31, 2023 and 2022:


	December 31,
	2023		2022
Remaining lease term and discount rate:
Weighted average remaining lease term (years)	3.44		2.00
Weighted average discount rate	3.91	%	4.25	%

INVENTORIES (Tables)

12 Months Ended

Dec. 31, 2023

Inventory Disclosure [Abstract]

Inventory

At December 31, 2023 and 2022, inventory consisted of the following:


	December 31,
	2023		2022
Raw materials	$	235,062	$	167,135
Work-in-process	81,438		79,126
Finished goods	228,895		146,911
Total inventory	$	545,395	$	393,172

PARENT COMPANY ONLY CONDENSED FINANCIAL INFORMATION, Condensed Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Current assets [Abstract]
Cash and cash equivalents	$ 182,090	$ 247,951	$ 562,548
Accounts receivable	283,186	182,936
Prepaid expenses	20,023	15,607
Total current assets	1,176,110	963,806
Deferred tax assets	20,271	6,703
Property, plant and equipment, net	201,848	82,875
Total assets	1,490,908	1,235,500
Liabilities and Equity
Long-Term borrowings	53,952	18,687
Income taxes payable	6,401	3,469
FIN-48 payable	12,149	6,686
Total liabilities	564,746	423,329
Total stockholders' equity	767,390	674,856
Total liabilities and equity	1,490,908	1,235,500
Related Party
Current assets [Abstract]
Other receivables	2,432	3,322
Nonrelated Party
Current assets [Abstract]
Other receivables	40,065	29,617
Parent Company
Current assets [Abstract]
Cash and cash equivalents	41,616	23,853
Accounts receivable	988	24
Prepaid expenses	385	134
Total current assets	51,968	29,028
Deferred tax assets	20,271	6,703
Property, plant and equipment, net	134	0
Investment in consolidated subsidiaries and equity method investee	733,382	653,926
Total assets	805,755	689,657
Liabilities and Equity
Long-Term borrowings	14,120	0
Accounts payable	524	236
Other Notes Payable	5,176	4,409
Income taxes payable	6,402	3,469
FIN-48 payable	12,149	6,686
Total liabilities	38,371	14,800
Total stockholders' equity	767,384	674,857
Total liabilities and equity	805,755	689,657
Parent Company \| Related Party
Current assets [Abstract]
Other receivables	3,176	0
Parent Company \| Nonrelated Party
Current assets [Abstract]
Other receivables	$ 5,803	$ 5,017

ACCOUNTS RECEIVABLE - Summary of Allowance For Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 0
Provision for credit loss	(2,731)	$ 0
Ending balance	4,830	0
Cumulative Effect, Period of Adoption, Adjustment
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 2,099	0
Ending balance		$ 2,099

LEASES - Operating Lease Supplemental Cash Flow (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Operating cash outflow from operating leases	$ 3,580	$ 2,816	$ 2,451
Operating lease right-of-use assets obtained in exchange for new operating lease liabilities	$ 8,195	$ 1,054	$ 1,818

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Government Subsidies (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) grant	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Government Subsidies [Abstract]
Number of grants received \| grant	7
Subsidies recognized as reductions of relevant expenses	$ 1,740	$ 1,201	$ 11,260
Subsidies recognized as other income	$ 533	$ 306	$ 200

ACCOUNTS RECEIVABLE

12 Months Ended

Dec. 31, 2023

Receivables [Abstract]

ACCOUNTS RECEIVABLE

At December 31, 2023 and 2022, accounts receivable consisted of the following:


	December 31,
	2023		2022
Accounts receivable	$	288,016	$	182,936
Less: Allowance for credit losses	(4,830)		-
Total	$	283,186	$	182,936

The $100,250 increase in accounts receivable for the year ended December 31, 2023 corresponds to a $168,891 increase in revenue for the same period.


	December 31,
	2023		2022
Cumulative effect of change in accounting principle under ASC 326, before tax, as of January 1, 2023	$	(2,099)	$	—
Provision for credit loss	(2,731)		—
Allowance for credit losses, before tax, as of December 31, 2023	$	(4,830)	$	—

The Company assesses collectability by reviewing accounts receivable on a general basis where similar characteristics exist and on an individual basis when the Company identifies specific customers with known disputes or collectability issues. In determining the amount of the allowance for credit losses, the Company considers historical collectability based on past due status, the age of the accounts receivable balances, credit quality of the Company’s customers based on ongoing credit evaluations, current economic conditions, reasonable and supportable forecasts of future economic conditions, and other factors that may affect the Company’s ability to collect from customers. As a result of the Company’s adoption of ASC 326 as of January 1, 2023 (Note 2), the Company recorded an allowance for credit losses as of December 31, 2023, as compared to no allowance for credit losses as of December 31, 2022.

STOCK-BASED COMPENSATION, Assumptions Used to Determine Fair Value of Share Options Granted (Details) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
2023 Stock Option Incentive Plan \| Minimum
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected term (in years)	1 year 6 months
2023 Stock Option Incentive Plan \| Maximum
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected term (in years)	4 years 6 months
Employee stock option plan
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Granted (in shares)	2,230,500	1,653,300	421,200
Employee stock option plan \| Service Period Based
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected term (in years)			6 years 3 months
Expected dividend rate (as a percent)	0.00%	0.00%	0.00%
Employee stock option plan \| Service Period Based \| Minimum
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Fair value of common share (in dollars per share)	$ 11.85	$ 16.83	$ 12.79
Expected term (in years)	5 years 6 months	5 years 6 months
Expected volatility rate (as a percent)	84.95%	49.43%	48.53%
Risk free interest rate (as a percent)	4.16%	1.70%	1.00%
Employee stock option plan \| Service Period Based \| Maximum
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Fair value of common share (in dollars per share)	$ 17.23	$ 25.45	$ 17.02
Expected term (in years)	6 years 3 months	6 years 3 months
Expected volatility rate (as a percent)	86.45%	50.87%	49.47%
Risk free interest rate (as a percent)	4.69%	3.04%	1.44%
Employee stock option plan \| 2023 Stock Option Incentive Plan
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Fair value of common share (in dollars per share)	$ 14.87
Employee stock option plan \| 2023 Stock Option Incentive Plan \| Minimum
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected volatility rate (as a percent)	60.00%
Risk free interest rate (as a percent)	1.50%
Employee stock option plan \| 2023 Stock Option Incentive Plan \| Maximum
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected volatility rate (as a percent)	60.60%
Risk free interest rate (as a percent)	2.75%

LONG-TERM BORROWINGS - Summary of Scheduled Principal Payments (Details) ¥ in Thousands, $ in Thousands	Dec. 31, 2023 USD ($)	Dec. 31, 2023 CNY (¥)	Dec. 31, 2022 USD ($)
Long-Term Debt, by Current and Noncurrent [Abstract]
2024	$ 6,783
2025	44,087
2026	1,855
2027	1,929
2028 \| ¥		¥ 2,007
Thereafter	4,074
Long-term debt	$ 60,735		$ 21,009

- Definition

Amount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

+ References + Details

LONG-TERM BORROWINGS

12 Months Ended

Dec. 31, 2023

Long-Term Debt, by Current and Noncurrent [Abstract]

LONG-TERM BORROWINGS

At December 31, 2023 and 2022, long-term borrowings consisted of the following:


	December 31,
	2023		2022
Loan from China Merchants Bank	$	13,362	$	15,265
Loans from Bank of China	5,013		5,744
Loan from Bank of Shanghai	14,120		—
Loans from China CITIC Bank	28,240		—
Less: Current portion	(6,783)		(2,322)
	$	53,952	$	18,687

The loan from China Merchants Bank is for the purpose of purchasing property in Lingang, Shanghai. The loan is repayable in 120 installments with the last installment due in November 2030, with an annual interest rate of 4.65%. The loan is pledged by the property of ACM Shengwei and guaranteed by ACM Shanghai.

Two loans from Bank of China are for the purpose of funding ACM Shanghai project expenditures. The loans bear interest at an annual rate of 2.6% and are repayable in 6 installments, with the last installments due in June 2024 and September 2024.

The loan from Bank of Shanghai is for the purpose of funding ACM Shanghai project expenditures. The loan bears interest at an annual rate of 2.85%, and will be fully repaid in April 2025.

The first loan from China CITIC Bank is for the purpose of funding ACM Shanghai project expenditures. The loan bears interest at an annual rate of 3.40% and are repayable in 4 installments, with the last installment due in August 2025.

The second loan from China CITIC bank is for the purpose of funding ACM's general corporate expenses and working capital. The loan bears interest at an annual rate of 4.50% payable quarterly, and the principal amount is repayable in 4 installments, with the last installment due in December 2025.

As of December 31, 2023 and December 31, 2022, the total carrying amount of long-term loans was $60,735 and $21,009, compared with an estimated fair value of $56,462 and $18,538, respectively. The fair value of the long-term loans is estimated by discounting cash flows using interest rates currently available for debts with similar terms and maturities (Level 2 fair value measurement). Refer to Note 2 for an explanation of the fair value hierarchy structure.

Scheduled principal payments for the outstanding long-term loans, including the current portion, as of December 31, 2023 are as follows:


Year ending December 31,
2024	$	6,783
2025	44,087
2026	1,855
2027	1,929
2028	2,007
Thereafter	4,074
	$	60,735

For the years ended December 31, 2023 and 2022, respectively, $1,100 and $845 of interest expense related to long-term borrowings was incurred. For the year ended December 31, 2021, $1,040 of interest related to long-term borrowings was incurred, of which $65 was charged to interest expense and $975 was capitalized as other long-term assets.

INCOME TAXES - Summary of Income Tax Benefit and Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Current:
U.S. federal	$ (12,757)	$ (479)	$ (91)
U.S. state	(150)	(18)	(2)
Total U.S. current tax benefit (expense)	(12,907)	(497)	(93)
Foreign	(19,696)	(11,139)	(2,195)
Total current tax expense	(32,603)	(11,636)	(2,288)
Deferred:
U.S. federal	7,316	(10,927)	2,089
U.S. state	63	8	0
Total U.S. deferred tax benefit (expense)	7,379	(10,919)	2,089
Foreign	5,860	5,757	65
Total deferred tax benefit	13,239	(5,162)	2,154
Total income tax expense	$ (19,364)	$ (16,798)	$ (134)

LONG-TERM INVESTMENTS

12 Months Ended

Dec. 31, 2023

Long-Term Investments [Abstract]

LONG-TERM INVESTMENTS

On September 6, 2017, ACM and Ninebell Co., Ltd. (“Ninebell”), a Korean company that is one of the Company’s principal material suppliers, entered into an ordinary share purchase agreement, effective as of September 11, 2017, pursuant to which Ninebell issued to ACM ordinary shares representing 20% of Ninebell’s post-closing equity for a purchase price of $1,200, and a common stock purchase agreement, effective as of September 11, 2017, pursuant to which ACM issued 400,002 shares of Class A common stock to Ninebell for a purchase price of $1,000 at $2.50 per share. The investment in Ninebell is accounted for under the equity method.

On June 27, 2019, ACM Shanghai and Shengyi Semiconductor Technology Co., Ltd. (“Shengyi”), a company based in Wuxi, China that is one of the Company’s component suppliers, entered into an agreement pursuant to which Shengyi issued to ACM Shanghai shares representing 15% of Shengyi’s post-closing equity for a purchase price of $109. The investment in Shengyi is accounted for under the equity method. In September 2023, the Company invested additional

RMB 6,100 ($900) to Shengyi. As the additional investment is not in substance common stock, the Company measures the additional investment in Shengyi at measurement alternative.

On September 5, 2019, ACM Shanghai entered into a Partnership Agreement with six other investors, as limited partners, and Beijing Shixi Qingliu Investment Co., Ltd., as general partner and manager, with respect to the formation of Hefei Shixi Chanheng Integrated Circuit Industry Venture Capital Fund Partnership (LP), a Chinese limited partnership based in Hefei, China. Pursuant to such Partnership Agreement, on September 30, 2019, ACM Shanghai invested RMB 30,000 ($4,200), which represented 10% of the partnership’s total subscribed capital. The investment in Hefei Shixi Chanheng Integrated Circuit Industry Venture Capital Fund Partnership (LP) is accounted for under the equity method in accordance with ASC 323-30-S99-1.

On October 29, 2021, ACM Shanghai and Waferworks (Shanghai) Co., Ltd, or Waferworks, a company based in Shanghai, China, and one of the Company’s customers, entered into an agreement pursuant to which Waferworks issued to ACM Shanghai shares representing 0.25% of Waferworks’ post-closing equity for a purchase price of $1,568. As the investment is not in substance common stock and there is no readily determinable fair value, the Company measures the investment in Waferworks at measurement alternative.

On August 17, 2022, ACM Singapore and Wooil Flucon Co., Ltd. (“Wooil”), a company based in Korea and a potential component supplier to the Company, entered into an agreement pursuant to which Wooil, on September 1, 2022, issued to ACM Singapore shares representing 20% of Wooil’s post-closing equity for a purchase price of $1,000. The investment in Wooil is accounted for under the equity method.

In September 2023, ACM Shanghai entered into a partnership agreement with Company A to invest RMB 30,000 ($4,200), which represented 4.37% of the partnership's total subscribed capital. Since there is no readily determinable fair value, the Company measures the investments at measurement alternative.

In November 2023, ACM Shanghai entered into a partnership agreement with Company B to invest RMB 6,600 ($930), which represented 1.38% of the partnership's total subscribed capital. Since there is no readily determinable fair value, the Company measures the investments at measurement alternative.


	December 31,
Equity investee:	2023		2022
Ninebell	$	5,632	$	5,199
Wooil	1,003		1,011
Shengyi	1,693		1,168
Hefei Shixi	9,174		8,645
Subtotal	17,502		16,023
Investments accounted for using measurement alternative:
Waferworks	1,412		1,436
Shengyi	857		—
Company A	4,236		—
Company B	932		—
Other	2,941		—
Total	$	27,880	$	17,459

LONG-TERM INVESTMENTS - Schedule of Long Term Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Long-Term Investment [Line Items]
Total	$ 27,880	$ 17,459
Equity investee:
Long-Term Investment [Line Items]
Total	17,502	16,023
Equity investee: \| Ninebell
Long-Term Investment [Line Items]
Total	5,632	5,199
Equity investee: \| Wooil
Long-Term Investment [Line Items]
Total	1,003	1,011
Equity investee: \| Shengyi
Long-Term Investment [Line Items]
Total	1,693	1,168
Equity investee: \| Hefei Shixi
Long-Term Investment [Line Items]
Total	9,174	8,645
Investments accounted for using measurement alternative: \| Shengyi
Long-Term Investment [Line Items]
Total	857	0
Investments accounted for using measurement alternative: \| Waferworks
Long-Term Investment [Line Items]
Total	1,412	1,436
Investments accounted for using measurement alternative: \| Company A
Long-Term Investment [Line Items]
Total	4,236	0
Investments accounted for using measurement alternative: \| Company B
Long-Term Investment [Line Items]
Total	932	0
Investments accounted for using measurement alternative: \| Other
Long-Term Investment [Line Items]
Total	$ 2,941	$ 0

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Recently Adopted Accounting Pronouncements (Details) ¥ in Thousands	Dec. 31, 2023 CNY (¥)
Cumulative Effect, Period of Adoption, Adjustment \| Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity, Including Portion Attributable To Noncontrolling Interest, Including Prior Period Adjustment	¥ (1,769)

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 405
-SubTopic 50
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147477123/405-50-65-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 13
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482477/820-10-65-13

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482477/820-10-65-13

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 5
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479654/326-10-65-5

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 5
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479654/326-10-65-5

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 5
-Subparagraph (b)(1)
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-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 88: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (e)(4)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 89: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 90: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481925/310-20-65-2

Reference 91: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481925/310-20-65-2

Reference 92: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480424/946-10-50-3

+ Details

PROPERTY, PLANT AND EQUIPMENT, NET (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2023 CNY (¥)	Feb. 28, 2023 USD ($)	Feb. 28, 2023 CNY (¥)
Property, Plant and Equipment, Net, by Type [Abstract]
Total cost	$ 112,911	$ 56,433
Less: Total accumulated depreciation and amortization	(17,503)	(10,047)
Construction in progress	106,440	36,489
Total property, plant and equipment, net	201,848	82,875
Depreciation expense	6,912	4,839	$ 2,099
Buildings and plants
Property, Plant and Equipment, Net, by Type [Abstract]
Total cost	83,109	35,864
Buildings and plants \| Shengwei Research (Shanghai), Inc.
Property, Plant and Equipment, Net, by Type [Abstract]
Total cost	35,264			¥ 249,746	$ 47,201	¥ 338,848
Buildings and plants \| Zhangjiang
Property, Plant and Equipment, Net, by Type [Abstract]
Total cost	47,845			¥ 338,848
Manufacturing equipment
Property, Plant and Equipment, Net, by Type [Abstract]
Total cost	16,556	9,298
Office equipment
Property, Plant and Equipment, Net, by Type [Abstract]
Total cost	4,953	3,691
Transportation equipment
Property, Plant and Equipment, Net, by Type [Abstract]
Total cost	404	407
Leasehold improvement
Property, Plant and Equipment, Net, by Type [Abstract]
Total cost	$ 7,889	$ 7,173

SHORT-TERM BORROWINGS (Tables)

12 Months Ended

Dec. 31, 2023

Debt Disclosure [Abstract]

Short-Term and Long-Term Borrowings

At December 31, 2023 and December 31, 2022, short-term borrowings consisted of the following:


	December 31,
	2023	2022
Line of credit up to RMB 150,000 from China Everbright Bank,
1)due on August 17, 2023 with an annual interest rate of 3.40%.	—	8,616
2)due on September 1, 2023 with an annual interest rate of 3.60%.	—	8,616


3)due on December 16, 2023 with an annual interest rate of 3.00%	-	4,308
4)due on August 29,2024 with an annual interest rate of 3.00%.	2,463	-
Line of credit up to RMB 100,000 from Bank of Communications,
1)due on August 11, 2023 with an annual interest rate of 3.60%.	—	8,616
2)due on September 5, 2023 with an annual interest rate of 3.50%.	—	5,744
Line of credit up to RMB 40,000 from Bank of China,
1)due on August 26, 2023 with an annual interest rate of 3.15%.	—	5,744
Line of credit up to RMB 40,000 from Bank of China,
1)due on September 7, 2024 with an annual interest rate of 2.87%	5,648	—
Line of credit up to RMB 100,000 from China Merchants Bank,
1)due on July 21, 2023 with an annual interest rate of 3.50%	—	1,292
2)due on July 27, 2023 with an annual interest rate of 3.50%	—	1,292
3)due on August 1, 2023 with an annual interest rate of 3.50%	—	1,292
4)due on August 3, 2023 with an annual interest rate of 3.50%	—	1,292
5)due on August 7, 2023 with an annual interest rate of 3.50%	—	1,293
6)due on August 14, 2023 with an annual interest rate of 3.50%	—	1,293
7)due on August 15, 2023 with an annual interest rate of 3.50%	—	1,293
8)due on August 21, 2023 with an annual interest rate of 3.50%	—	1,005
9)due on August 28, 2023 with an annual interest rate of 3.50%	—	1,292
10)due on September 13, 2023 with an annual interest rate of 3.50%	—	1,292
11)due on September 20, 2023 with an annual interest rate of 3.50%	—	1,293
12)due on October 7, 2023 with an annual interest rate of 3.50%	—	431
Line of credit up to RMB 200,000 from China Merchants Bank,
1)due on August 7,2024 with an annual interest rate of 3.00%.	1,271	-
2)due on August 8,2024 with an annual interest rate of 3.00%.	1,271	-
3)due on August 9,2024 with an annual interest rate of 3.00%.	1,271	-
4)due on August 14,2024 with an annual interest rate of 3.00%.	1,271	-
5)due on August 17,2024 with an annual interest rate of 3.00%.	1,271	-
6)due on August 20,2024 with an annual interest rate of 3.00%.	1,271	-
7)due on August 21,2024 with an annual interest rate of 3.00%.	1,271	-
8)due on August 22,2024 with an annual interest rate of 3.00%.	1,271	-
9)due on August 24,2024 with an annual interest rate of 3.00%.	1,271	-
10)due on August 27,2024 with an annual interest rate of 3.00%.	1,271	-
11)due on August 29,2024 with an annual interest rate of 3.00%.	1,271	-
12)due on August 30,2024 with an annual interest rate of 3.00%.	1,271	-
13)due on September 3,2024 with an annual interest rate of 3.00%.	1,271	-
14)due on September 5,2024 with an annual interest rate of 3.00%.	1,270	-
15)due on September 6,2024 with an annual interest rate of 3.00%.	1,270	-
16)due on September 10,2024 with an annual interest rate of 3.00%.	1,270	-
17)due on September 12,2024 with an annual interest rate of 3.00%.	1,270	-
Line of credit up to KRW 500,000 from Industrial Bank of Korea,
1)due on July 12,2024 with an annual interest rate of 6.03%.	77	-
Line of credit up to KRW 2,000,000 from Industrial Bank of Korea,


1)due on December 15,2024 with an annual interest rate of 4.27%.	1,544		-
Total	$	31,335	$	56,004

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

12 Months Ended

Dec. 31, 2023

Accounting Policies [Abstract]

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Basis of Presentation and Principles of Consolidation

The Company’s consolidated financial statements include the accounts of ACM and its subsidiaries, including ACM Shanghai and its subsidiaries. ACM’s subsidiaries are those entities in which ACM, directly and indirectly, controls more than a majority of the voting power. All significant intercompany transactions and balances have been eliminated upon consolidation. The consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”)

Use of Estimates

The preparation of the condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the balance sheet date and the reported revenues and expenses during the reported period in the condensed consolidated financial statements and accompanying notes. The Company’s significant accounting estimates and assumptions include, but are not limited to, those used for revenue recognition and deferred revenue, the valuation and recognition of fair value of certain short-term and long-term investments, stock-based compensation arrangements, realization of deferred tax assets, assessment for impairment of long-lived assets and long-term investments, allowance for credit losses, inventory valuation, useful lives of property, plant and equipment and useful lives of intangible assets.

Management evaluates these estimates and assumptions on a regular basis. Actual results could differ from those estimates and assumptions.

Common Stock Split

All prior period share and per share amounts and common stock presented in the accompanying financial statements and these notes thereto has been retroactively adjusted to reflect the impact of the Stock Split. Proportional adjustments were also made to outstanding awards under the Company’s stock-based compensation plans.

Reclassifications

Certain prior year amounts in the consolidated financial statements have been reclassified to conform with the current year presentation. These classifications had no impact on the Company’s results of operations.

Cash and Cash Equivalents

Cash and cash equivalents consist of cash on hand and bank deposits that are unrestricted as to withdrawal and use, and highly liquid investments with an original maturity date of three months or less at the date of purchase. At times, cash deposits may exceed government-insured limits.

The following table presents cash and cash equivalents, according to jurisdiction as of December 31, 2023 and 2022:


	December 31,
	2023		2022
United States	$	43,614	$	25,011
Mainland China	70,418		129,695
China Hong Kong	64,057		89,187
Korea	3,934		4,007
Singapore	67		51
Total	$	182,090	$	247,951

The amounts in mainland China do not include short-term and long-term time deposits which totaled $121,342 and $172,448 at December 31, 2023 and 2022, respectively.

Cash held in the U.S. exceeds the Federal Deposit Insurance Corporation (“FDIC”) insurance limits and is subject to risk of loss. No losses have been experienced to date.

Cash amounts at the banks in mainland China are subject to a series of risk control regulatory standards from mainland China bank regulatory authorities. ACM’s subsidiaries in mainland China are required to obtain approval from the State Administration of Foreign Exchange (“SAFE”) to transfer funds into or out of mainland China. SAFE requires a valid agreement to approve the transfers, which are processed through a bank. Other than these mainland China foreign exchange restrictions, ACM’s subsidiaries in mainland China are not subject to any mainland China restrictions and limitations on its ability to transfer funds to ACM Research or among our other subsidiaries. However, cash held by ACM’s subsidiaries in mainland China does exceed applicable insurance limits and is subject to risk of loss, although no such losses have been experienced to date.

ACM California periodically procures goods and services on behalf of ACM Shanghai. For these transactions, ACM Shanghai makes cash payments to ACM California in accordance with applicable transfer pricing arrangements. For the years ended December 31, 2023 and December 31, 2022, cash payments from ACM Shanghai to ACM California for the procurement of goods and services were $42.5 million and $30.2 million, respectively. ACM California periodically borrows funds for working capital advances from its direct parent, CleanChip. ACM California repays or renews these intercompany loans in accordance with their terms.

For sales through CleanChip and ACM Research, a certain amount of sales or advance payments from customer proceeds is repatriated back to ACM Shanghai, a subsidiary, in accordance with applicable transfer pricing arrangements in the ordinary course of business. ACM Research provides services to certain customers located in the U.S., Europe and other regions outside of mainland China to support the evaluation of first tools and provide support for tools under warranty on behalf of ACM Shanghai. For these transactions, ACM Shanghai makes cash payments to ACM Research in accordance with applicable transfer pricing arrangements.

For the year ended December 31, 2023, ACM Shanghai paid $19,200 in dividends to ACM Research.

Subsequent to June 30, 2020, with the exception of sales and services-related transfer-pricing payments in the ordinary course of business, and dividends paid by ACM Shanghai to ACM Research, no cash transfers or other payments or distributions have been made between ACM Research and ACM Shanghai. ACM Research intends to retain any future

earnings to finance the operations and expenses of the business, and do not expect to distribute earnings or declare or pay any dividends in the foreseeable future.

Amounts held in Korea exceed the Korea Deposit Insurance Corporation (“KDIC”) insurance limits and are subject to risk of loss. No losses have been experienced to date.

There is no additional restriction for the transfer of cash from bank accounts in the U.S., Korea, Singapore, and Hong Kong.

Time Deposits

Time deposits are deposited with banks in mainland China with fixed terms and interest rates which cannot be withdrawn before maturity, and are presented as short-term deposits and long-term deposits in the consolidated financial statements based on their expected time of collection. They are also subject to the risk control regulatory standards described above upon maturity. Time deposits consisted of the following:


	December 31,
	2023		2022
Deposit in China Merchant Bank which matured on January 29, 2023 with an annual interest rate of 2.25%	$	—	$	38,772
Deposit in China Everbright Bank which matured on January 29, 2023 with an annual interest rate of 2.25%	—		14,360
Deposit in China Everbright Bank which matured on May 22, 2023 with an annual interest rate of 5.07%	—		3,000
Deposit in China Industrial Bank which matured on January 30, 2023 with an annual interest rate of 2.15%	—		14,360
Deposit in China Merchant Bank which matured on January 29, 2024 with an annual interest rate of 2.85%	29,797		28,720
Deposit in Bank of Ningbo which matured on February 17, 2024 with an annual interest rate of 2.85%	44,630		43,080
Deposit in Shanghai Pudong Development Bank which matures on October 20, 2025 with an annual interest rate of 3.10%	7,322		7,180
Deposit in Shanghai Pudong Development Bank which matures on November 14, 2025 with an annual interest rate of 3.10%	7,307		7,180
Deposit in Shanghai Pudong Development Bank which matures on December 8, 2025 with an annual interest rate of 3.10%	4,376		4,308
Deposit in Shanghai Pudong Development Bank which matures on December 15, 2025 with an annual interest rate of 3.10%	4,373		4,308
Deposit in Shanghai Pudong Development Bank which matures on December 30, 2025 with an annual interest rate of 3.10%	2,912		7,180
Deposit in China Industrial Bank which matures on January 30, 2026 with an annual interest rate of 3.15%	14,528		—
Deposit in China Everbright Bank which matured on January 5, 2024 with an annual interest rate of 5.38%	3,079		—
Deposit in China Everbright Bank which matures on May 22, 2024 with an annual interest rate of 5.38%	3,018		—
	$	121,342	$	172,448

For the years ended December 31, 2023 and 2022, respectively, interest income related to time deposits was $3,689 and $3,472, respectively.

Accounts Receivable

Prior to adoption of Accounting Standards Update, or ASU, 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASC 326”), the Company reviews its accounts receivable on a periodic basis and makes general and specific allowances when there is doubt as to the collectability of individual balances. After adoption of ASC 326, as of January 1, 2023, the Company assesses collectability by reviewing accounts receivable on a collective basis where similar characteristics exist and on an individual basis when the Company identifies specific customers with known disputes or collectability issues. In determining the amount of the allowance for credit losses, the Company considers historical collectability based on past due status, the age of the accounts receivable balances, credit quality of the Company’s customers based on ongoing credit evaluations, current economic conditions, reasonable and supportable forecasts of future economic conditions, and other factors that may affect the Company’s ability to collect from customers. At December 31, 2023, and 2022, the Company, based on a review of its outstanding balances and its customers, determined the allowance for credit losses were $4,830 and $0, respectively.

Land Use Right, Net

The land use right represents the cost to purchase a right to use state-owned land in mainland China with lease terms of 50 years expiring in 2070, for which an upfront lump-sum payment was made during the year ended December 31, 2021. The land use rights are treated as operating lease. The Company classifies the land use right as non-current assets on the consolidated balance sheets (note 7).

Inventory

Inventory consists of raw materials and related goods, work-in-progress, finished goods, and other consumable materials such as spare parts.

Inventory was recorded at the lower of cost or net realizable value at December 31, 2023 and 2022.

•The cost of a general inventory item is determined using the moving weighted average method. The cost of an inventory item purchased specifically for a customized product is determined using the specific identification method. Low-cost consumable materials and packaging materials are expensed as incurred.

•Net realizable value is the estimated selling price, in the ordinary course of business, less estimated costs to complete or dispose.

The Company assesses the recoverability of all inventories quarterly to determine if any adjustments are required. Potential excess or obsolete inventory is written down based on management’s analysis of inventory levels and estimates of future 12-month demand and market conditions.

Property, Plant and Equipment, Net

Property, plant and equipment are recorded at cost less accumulated depreciation and any provision for impairment in value. Depreciation begins when the asset is placed in service and is calculated by using the straight-line method over the estimated useful life of an asset (or, if shorter, over the lease term). Betterments or renewals are capitalized when incurred.

Estimated useful lives of assets are as follows:


Buildings and plants			30 years
Computer and office equipment			3 to 5 years
Furniture and fixtures			5 years
Leasehold improvements			shorter of lease term or estimated useful life
Electronic equipment			3 to 5 years
Manufacturing equipment			for small to medium-sized equipment, 5 to 10 years; for large equipment, estimated by purchasing department at time of acceptance
Transportation equipment			4 to 5 years

Expenditures for maintenance and repairs that neither materially add to the value of the property nor appreciably prolong the life of the property are charged to expense as incurred. Upon retirement or sale of an asset, the cost of the asset and the related accumulated depreciation are eliminated from the accounts and any resulting gain or loss is credited or charged to income.

Intangible Assets, Net

Intangible assets consist of purchase software. Assets are valued at cost at the time of acquisition and are amortized over their beneficial periods.

Valuation of Long-Lived Assets

Long-lived assets are evaluated for impairment whenever events or changes in circumstance indicate that the carrying value of the assets may not be fully recoverable or that the useful life of the assets is shorter than the Company had originally estimated. When these events or changes occur, the Company evaluates the impairment of the long-lived assets by comparing the carrying value of the assets to an estimate of future undiscounted cash flows expected to be generated from the use of the assets and their eventual disposition. If the sum of the expected future undiscounted cash flows is less than the carrying value of the assets, the Company recognizes an impairment loss based on the excess of the carrying value over the fair value. No impairment charge was recognized for either of the periods presented.

Leases

The Company determines if an arrangement is a lease at inception. Operating leases are included in operating lease right-of-use (“ROU”) assets, and operating lease liabilities in the consolidated balance sheets.

ROU assets represent the Company’s right to use an underlying asset for the lease term, and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. As most of the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. The Company uses the implicit rate when readily determinable. The operating lease ROU asset also includes any lease payments made and excludes lease incentives. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Operating lease expense is recognized on a straight-line basis over the lease term.

Revenue Recognition

The Company derives revenue principally from the sale of semiconductor capital equipment. Revenue from contracts with customers is recognized using the following five steps pursuant ASC Topic 606, Revenue from Contracts with Customers:

1.Identify the contract(s) with a customer;

2.Identify the performance obligations in the contract;

3.Determine the transaction price;

4.Allocate the transaction price to the performance obligations in the contract; and

5.Recognize revenue when (or as) the entity satisfies a performance obligation.

Identify the contract(s) with a customer. The Company generally considers written documentation including, but not limited to, signed purchase orders, master agreements, and sales orders as contracts, provided it has approval and commitment from the customer, the rights of the parties are identified, payment terms are identified, the contract has commercial substance, and collection is probable. Collectability is assessed based on management’s assessment of the customer’s creditworthiness, historical payment experience, as well as other relevant factors.

Identify the performance obligations in the contract. Performance obligations are accounted for separately if they are distinct. A good or service is distinct if the customer can benefit from the good or service either on its own or together with other resources that are readily available to the customer, and the good or service is distinct in the context of the contract. The Company’s performance obligations generally include sales of tools and spare parts. In addition, customer contracts can contain provisions for installation, training, software updates, most-favored pricing for spare parts, and other items which have been deemed immaterial in the context of the contract.

Determine the transaction price. The transaction price for the Company’s contracts with customers may include fixed and variable consideration. The Company includes variable consideration in the transaction price to the extent that it is probable that a significant reversal of revenue will not occur in the future based on the Company’s historical experience with similar arrangements.

Allocate the transaction price to the performance obligations in the contract. For contracts that contain multiple performance obligations, the Company allocates the transaction price to the performance obligations on a relative standalone selling price basis. The Company defers revenue associated with spare parts, sold together with its tools, based on its stand-alone observable selling prices or using an expected cost-plus-margin approach when a stand-alone selling price is not directly observable, and recognizes revenue upon subsequent delivery.

Recognize revenue when, or as, a performance obligation is satisfied. The Company recognizes revenue from tools and spare parts at a point in time, when the Company has satisfied its performance obligation. The Company’s sales arrangements do not include a general right of return. For shipments made to a customer that has not previously accepted a specific type of tool (“first tools”), revenues are recognized when the tools are accepted by the customer. For shipments made to a customer that has previously accepted a specific type of tool ("repeat shipment"), revenues are recognized upon shipment or delivery because the Company can objectively demonstrate that the tools meet all the required customer specifications.

The Company’s warranties provide assurance that its products will function as expected and in accordance with certain specifications. The Company’s warranties are intended to safeguard the customer against existing defects and do not provide any incremental service to the customer. They are not separate performance obligations and are accounted for under FASB ASC Topic 460, Guarantees.

Contract liabilities include payments received from customers prior to the transfer of control of certain goods which are recorded as advances from customers, and spare parts sold together with its tools which are recorded as deferred revenue. The Company does not have contract assets.

Cost of Revenue

Cost of revenue primarily consists of: direct materials, comprised principally of parts used in assembling equipment, together with crating and shipping costs; direct labor, including salaries and other labor related expenses attributable to the Company’s manufacturing department; allocated overhead cost, such as personnel cost, depreciation expense, expenses associated with supply chain management and quality assurance activities, inventory provision, as well as shipping insurance premiums.

Research and Development Costs

Research and development costs relating to the development of new products and processes, significant improvements and refinements to existing products or the process of supporting customer evaluations of tools, and the development of new tools for evaluation by customers during the product demonstration process, are expensed as incurred.

Shipping and Handling Costs

Shipping and handling costs, which relate to transportation of products to customer locations, are charged to selling and marketing expense. For the years ended December 31, 2023, 2022 and 2021, shipping and handling costs included in sales and marketing expenses were $1,582, $1,507, and $923, respectively.

Borrowing Costs

Borrowing costs attributable directly to the acquisition, construction or production of qualifying assets that require a substantial period of time to be ready for their intended use or sale are capitalized as part of the cost of those assets. Income earned on temporary investments of specific borrowings pending their expenditure on those assets is deducted from borrowing costs capitalized. All other borrowing costs are recognized in interest expense in the consolidated statements of comprehensive income (loss) in the period in which they are incurred.

Warranty

For each of its products, the Company generally provides a standard assurance type warranty ranging from 12 to 36 months and covering replacement of the product during the warranty period. The Company accounts for the estimated warranty costs at the time revenue is recognized. Warranty obligations are affected by historical failure rates and associated replacement costs. Utilizing historical warranty cost records, the Company calculates a rate of warranty expenses to revenue to determine the estimated warranty charge. The Company updates these estimated charges on a regular basis. Warranty obligations are included in other payables and accrued expenses in the consolidated balance sheets. The following table shows changes in the Company’s warranty obligations for the years ended December 31, 2023, 2022 and 2021, respectively.


	Year Ended December 31,
	2023		2022		2021
Balance at beginning of period	$	8,780	$	6,631	$	3,975
Additions	7,969		5,379		5,026
Utilized	(6,915)		(3,230)		(2,370)
Balance at end of period	$	9,834	$	8,780	$	6,631

Government Subsidies

ACM Shanghai has received seven special government grants. The governmental grants contain certain operating conditions, and the Company is required to go through a government due diligence process once the project is complete. Unearned government subsidies received are deferred and recorded as other long-term liabilities (note 13) in the consolidated balance sheet until the criteria for such recognition are satisfied. Grant amounts are recognized in our statements of comprehensive income (loss) as follows:

•Government subsidies relating to current expenses are recorded as reductions of those expenses in the periods in which the current expenses are recorded. For the years ended December 31, 2023, 2022, and 2021, related government subsidies recognized as reductions of relevant expenses in the consolidated statements of comprehensive income (loss) were $1,740, $1,201 and $11,260, respectively.

•Government subsidies related to depreciable assets are credited to income over the useful lives of the related assets for which the grant was received. For the years ended December 31, 2023, 2022, and 2021, related government subsidies recognized as other income in the consolidated statements of comprehensive income (loss) were $533, $306, and $200, respectively.

Stock-based Compensation

ACM and ACM Shanghai grants stock options to employees and non-employee consultants and directors and accounts for those stock-based awards in accordance with FASB ASC Topic 718, Compensation – Stock Compensation.

Stock-based awards granted to employees and non-employee consultants and directors are measured at the fair value of the awards on the grant date and are recognized as expenses either (a) immediately on grant, if no vesting conditions are required or (b) using the graded vesting method, net of estimated forfeitures, over the requisite service period. The fair value of stock options is determined using the Black-Scholes valuation model when there are service and performance condition attached or the Monte Carlo valuation model when there is market condition attached. Stock-based compensation is charged to the category of operating expense corresponding to the service function of the employees and non-employee consultants and directors.

Income Taxes

The Company accounts for income taxes using the liability method whereby deferred tax asset and liability account balances are determined based on differences between the financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. The Company provides a valuation allowance, if necessary, to reduce deferred tax assets to their estimated realizable values.

In evaluating the ability to recover its deferred income tax assets, the Company considers all available positive and negative evidence, including its operating results, ongoing tax planning and forecasts of future taxable income on a jurisdiction-by-jurisdiction basis. In the event the Company determines that it would be able to realize its deferred income tax assets in the future in excess of their net recorded amount, it would make an adjustment to the valuation allowance that would reduce the provision for income taxes. Conversely, in the event that all or part of the net deferred tax assets are determined not to be realizable in the future, an adjustment to the valuation allowance would be charged to earnings in the period such determination is made.

Tax benefits related to uncertain tax positions are recognized when it is more likely than not that a tax position will be sustained during an audit. Interest and penalties related to unrecognized tax benefits are included within the provision for income tax.

Basic and Diluted Net Income per Share of Common Stock

Basic and diluted net income per share of common stock is calculated as follows:


	Year Ended December 31,
	2023		2022		2021
Numerator:
Net income	$	96,852	$	50,564	$	42,921
Less: Net income attributable to non-controlling interests	19,503		11,301		5,164
Net income available to common stockholders, basic	$	77,349	$	39,263	$	37,757
Less: Dilutive effect arising from stock-based awards by ACM Shanghai	1,841		584		108
Net income available to common stockholders, diluted	$	75,508	$	38,679	$	37,649
Weighted average shares outstanding, basic (1)	60,164,670		59,235,975		57,654,708
Effect of dilutive securities	4,705,873		6,105,796		7,702,008
Weighted average shares outstanding, diluted	64,870,543		65,341,771		65,356,716

Net income per share of common stock:
Basic	$	1.29	$	0.66	$	0.65
Diluted	$	1.16	$	0.59	$	0.58

(1)The results for 2021 have been adjusted to reflect the three-for-one stock split effected in the form of a stock dividend in March 2022. See Note 2 for details.

Basic and diluted net income per share of common stock is presented using the two-class method, which allocates undistributed earnings to common stock and any participating securities according to dividend rights and participation rights on a proportionate basis. Under the two-class method, basic net income per share of common stock is computed by dividing the sum of distributed and undistributed earnings attributable to common stockholders by the weighted average number of shares of common stock outstanding during the period. ACM did not have any participating securities outstanding during the three-year periods ending December 31, 2023.

ACM has been authorized to issue Class A and Class B common stock since redomesticating in Delaware in November 2016. The two classes of common stock are substantially identical in all material respects, except for voting rights. Since ACM did not declare any dividends during the years ended December 31, 2023, 2022 and 2021, the net income per share of common stock attributable to each class is the same under the “two-class” method. As such, the two classes of common stock have been presented on a combined basis in the consolidated statements of comprehensive income (loss) and in the above computation of net income per share of common stock.

Diluted net income per share of common stock reflects the potential dilution from securities, including stock options, that could share in ACM’s earnings. Certain potential dilutive securities were excluded from the net income per share calculation because the impact would be anti-dilutive. The number of potentially dilutive shares that were not included in

the calculation of diluted net income per share in the periods presented where their inclusion would be anti-dilutive were 3,651,337, 1,795,340 and 98,800 the years ended December 31, 2023, 2022, and 2021, respectively.

Comprehensive Income (loss)

The Company applies FASB ASC Topic 220, Comprehensive Income, which establishes standards for the reporting and display of comprehensive income or loss, requiring its components to be reported in a financial statement with the same prominence as other financial statements. The Company’s comprehensive income (loss) includes net income and foreign currency translation adjustments and is presented in the consolidated statements of comprehensive income (loss).

Statutory Surplus Reserve

The income of ACM’s mainland China subsidiaries is distributable to their shareholders after transfers to reserves as required under relevant mainland China laws and regulations and the subsidiaries’ Articles of Association. As stipulated by the relevant laws and regulations in mainland China, mainland China subsidiaries are required to maintain reserves, including reserves for statutory surpluses and public welfare funds that are not distributable to shareholders. A mainland China subsidiary’s appropriations to the reserves are approved by its board of directors. At least 10% of annual statutory after-tax profits, as determined in accordance with mainland China accounting standards and regulations, is required to be allocated to the statutory surplus reserves. If the cumulative total of the statutory surplus reserves reaches 50% of a mainland China subsidiary’s registered capital, any further appropriation is optional.

Statutory surplus reserves may be used to offset accumulated losses or to increase the registered capital of a mainland China subsidiary, subject to approval from the relevant mainland China authorities, and are not available for dividend distribution to the subsidiary’s shareholders. The mainland China subsidiaries are prohibited from distributing dividends unless any losses from prior years have been offset. Except for offsetting prior years’ losses, however, statutory surplus reserves must be maintained at a minimum of 25% of share capital after such usage. ACM Shanghai estimated a statutory surplus reserve of $30,060 and $16,881 based on an accumulated profit as of December 31, 2023 and 2022, respectively, which is included in the statutory surplus reserve in the consolidated balance sheets.

Noncontrolling interests

A noncontrolling interest is recognized to reflect the portion of subsidiaries’ equity which is not attributable, directly or indirectly, to ACM Research. Consolidated net income on the consolidated statements of comprehensive income (loss) includes the net income attributable to noncontrolling interests. The cumulative results of operations attributable to noncontrolling interests are recorded as “noncontrolling interests” in the Company’s consolidated balance sheets.

Financial Instruments

The Company periodically invests in equity securities, and maintains an investment portfolio of various holdings, types, and maturities. For equity investments that do not have a readily determinable fair value, the Company classified them as long-term investments, and records them using either: 1) the measurement alternative which measures the equity investments at cost minus impairment, if any, plus or minus changes resulting from qualifying observable price changes; or 2) the equity method whereby the Company recognizes its proportional share of the income or loss from the equity method investment. The equity method is utilized when the equity investments are common stock or in substance common stock, and the Company does not have the ability to control the investee but is deemed to have the ability to exercise significant influence over the investee’s operating or financial policies. For equity investments that have a readily determinable fair value, the Company classified them as short-term investments, and records them at fair market value on a recurring basis based upon quoted market prices. Realized and unrealized gains and losses resulting from application of the measurement alternative, the impact of the application of the equity method to the Company’s equity investments, and recognition of changes in fair market value, as applicable, are recognized as non-operating income (expenses), net in the condensed consolidated statements of comprehensive income (loss).

The Company defines fair value as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities required or permitted to be recorded at fair value, the Company considers the principal or most advantageous market in which it would transact, and it considers assumptions that market participants would use when pricing the asset or liability.

A fair value hierarchy has been established that prioritizes the inputs to valuation techniques used to measure fair value. The level of an asset or liability in the hierarchy is based on the lowest level of input that is significant to the fair value measurement. Assets and liabilities carried at fair value are classified and disclosed in one of the following three categories:

Level 1: Valuations based on quoted prices in active markets for identical assets or liabilities with sufficient volume and frequency of transactions.

Level 2: Valuations based on observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active for identical assets or liabilities, or model-derived valuations techniques for which all significant inputs are observable in the market or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

Level 3: Valuations based on unobservable inputs to the valuation methodology that are significant to the measurement of fair value of assets or liabilities and based on non-binding, broker-provided price quotes and may not have been corroborated by observable market data.

The Company’s primary financial instruments include its cash, cash equivalents, short term and long term deposits, restricted cash, short-term and long-term investments, accounts receivable, other receivables, accounts payable, and short-term and long-term borrowings. The estimated fair value of cash and cash equivalents, restricted cash, short-term time deposits, accounts receivable, other receivable, accounts payable, and short-term borrowings approximates their carrying value due to the short period of time to their maturities.

All transfers between fair value hierarchy levels are recognized by the Company at the end of each reporting period. In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, an investment’s level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement in its entirety, requires judgment and considers factors specific to the investment. The inputs or methodology used for valuing financial instruments are not necessarily an indication of the risks associated with investment in those instruments.

Assets and liabilities measured at fair value on a recurring basis:


	Quoted Prices in Active Markets for Identical Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
As of December 31, 2023
Assets
Cash and cash equivalents	$	182,090	$	-	$	-	$	182,090
Short-term investments	21,312		-		-		21,312
	$	203,402	$	-	$	-	$	203,402

As of December 31, 2022
Assets
Cash and cash equivalents	$	247,951	$	-	$	-	$	247,951
Short-term investments	20,209		-		-		20,209
	$	268,160	$	-	$	-	$	268,160

Assets and liabilities measured at fair value on a non-recurring basis:


	Quoted Prices in Active Markets for Identical Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
As of December 31, 2023
Assets
Investments accounted for using measurement alternative	$	—	$	—	$	10,378	$	10,378
	$	—	$	—	$	10,378	$	10,378

The Company did not have any assets and liabilities measured at fair value on a non-recurring basis as of December 31, 2022.

The non-recurring fair value measurements to the carrying amount of equity investments accounted for using measurement alternative usually requires management to estimate a price adjustment for the different rights and obligations between a similar instrument of the same issuer with an observable price change in an orderly transaction and the investment held by the Company. These non-recurring fair value measurements were measured by using the observable transaction price and other unobservable inputs (level 3) as of the observable transaction dates.

Refer to Note 12 for fair value information related to the Company’s outstanding long-term borrowings as of December 31, 2023 and December 31, 2022.

Operating and Financial Risks

Concentration of Credit Risk

Financial instruments that potentially subject the Company to credit risk consist principally of cash and cash equivalents, time deposits, and accounts receivable. The Company deposits and invests its cash with financial institutions that management believes are creditworthy.

The Company is potentially subject to concentrations of credit risks in its accounts receivable and revenue. For the years ended December 31, 2023, 2022 and 2021 three customers accounted for 45.5%, three customers accounted for 43.8% of revenue, and two customers accounted for 48.9%, of revenue, respectively.

As of December 31, 2023 and 2022 four customers accounted for 59.1% and two customers accounted for 42.6%, respectively, of the Company’s accounts receivables. The Company believes that the receivable balances from these largest customers do not represent a significant credit risk based on past collection experience.

Interest Rate Risk

As of December 31, 2023 and 2022, the balance of the Company’s short term bank borrowings (note 9) were scheduled to mature at various dates within the following year and thus exposed the Company to modest interest rate risk. As of December 31, 2023, the Company’s long-term borrowings (note 12) carry a fixed interest rate, and the Company may be exposed to the fair value interest rate risk.

Liquidity Risk

The Company’s working capital at December 31, 2023 and 2022 was sufficient to meet its then-current requirements. The Company may, however, require additional cash due to changing business conditions or other future developments, including any investments or acquisitions the Company decides to pursue. In the long run, the Company intends to rely primarily on cash flows from operations and additional borrowings from financial institutions in order to meet its cash needs. If those sources are insufficient to meet cash requirements, the Company may seek to issue additional debt or equity.

Country Risk

The Company has significant investments in mainland China. The operating results of the Company may be adversely affected either directly or indirectly by changes in the political and social conditions in mainland China, by changes in mainland China government policies with respect to laws and regulations, anti-inflationary measures, currency conversion and remittance abroad, rates and methods of taxation, and export controls enacted by the U.S., Japan, and the Netherlands to restrict the sale of certain technology to mainland China, among other things.

Foreign Currency Risk and Translation

The Company’s consolidated financial statements are presented in U.S. dollars, which is the Company’s reporting currency, while the functional currency of ACM’s subsidiaries in mainland China and Korea are the Chinese Renminbi (“RMB”), and the Korean Won, respectively. Changes in the relative values of U.S. dollars and RMB affect the Company’s reported levels of revenues and profitability as the results of its operations are translated from RMB into U.S. dollars for reporting purposes. Since the Company has not engaged in any hedging activities, it cannot predict the impact of future exchange rate fluctuations on the results of its operations, and it may experience economic losses as a result of foreign currency exchange rate fluctuations.

Transactions of ACM’s subsidiaries involving foreign currencies are recorded in functional currency according to the rate of exchange prevailing on the date when the transaction occurs. The ending balances of the Company’s foreign currency accounts are converted into functional currency using the rate of exchange prevailing at the end of each reporting period. Net gains and losses resulting from foreign exchange fluctuations as marked to market at year-end are included in the consolidated statements of comprehensive income (loss).

In accordance with FASB ASC Topic 830, Foreign Currency Matters, the Company translates assets and liabilities into U.S. dollars from RMB or Korean Won using the rate of exchange prevailing at the applicable balance sheet date and the consolidated statements of comprehensive income (loss) and consolidated statements of cash flows are translated at an average rate during the reporting period. Adjustments resulting from the translation are recorded in stockholders’ equity as part of accumulated other comprehensive income (loss).

Recently Adopted Accounting Pronouncements

In June 2016, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASC 326”). ASC 326 replaced the pre-existing incurred loss impairment methodology with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. ASC 326 requires use of a forward-looking expected credit loss model for accounts receivables, loans and other financial instruments.

In November 2019, the FASB issued ASU 2019-10, Financial Instruments – Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842): Effective Dates. ASU 2019-10 defers the effective date of ASU 2016-13 for public filers that are considered small reporting companies (“SRC”) as defined by the SEC to fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. Since the Company was eligible to be a SRC based on its SRC determination as of November 15, 2019 (which was the issuance date of ASU 2019-10) in accordance with SEC regulations, the Company adopted amendments in ASC 326 for the year beginning January 1, 2023. Adoption of the standard requires using a modified retrospective approach through a cumulative-effect adjustment to retained earnings as of the effective date to align existing credit loss methodology with the new standard. The cumulative-effect adjustment, net of tax impact, to retained earnings as of January 1, 2023 was $(1,769).

In June 2022, the FASB issued ASU 2022-03—Fair Value Measurement (Topic 820): Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions (“ASU 2022-03”) which clarifies how the fair values of equity securities subject to contractual sale restrictions is determined (Topic 820). The amendment clarifies that a contractual sale restriction should not be considered in measuring fair value. It also requires certain qualitative and quantitative disclosures related to equity securities subject to contractual sale restrictions. The new guidance is required to be applied prospectively with any adjustments from the adoption of the amendments recognized in earnings and disclosed on the date of adoption. This guidance is effective for the Company for fiscal year beginning after December 15, 2023, and interim periods within those fiscal years. Early adoption is permitted. The Company early adopted ASU 2022-03 in the third quarter of 2023, and the adoption did not have a material impact on the Company’s financial position, results of operations and cash flows.

Recently issued accounting pronouncements not yet adopted

In November 2023, the FASB issued ASU No. 2023-07, Improvements to Reportable Segment Disclosures. This ASU updates reportable segment disclosure requirements by requiring disclosures of significant reportable segment expenses that are regularly provided to the Chief Operating Decision Maker (“CODM”) and included within each reported measure of a segment's profit or loss. This ASU also requires disclosure of the title and position of the individual identified as the CODM and an explanation of how the CODM uses the reported measures of a segment’s profit or loss in assessing segment performance and deciding how to allocate resources. The ASU is effective for annual periods beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. Adoption of the ASU should be applied retrospectively to all prior periods presented in the financial statements. Early adoption is also permitted. The Company is currently evaluating the provisions of this ASU and expect to adopt it for the year ending December 31, 2024.

In December 2023, the FASB issued ASU No. 2023-09, Improvements to Income Tax Disclosures (Topic 740). The ASU requires disaggregated information about a reporting entity’s effective tax rate reconciliation as well as additional information on income taxes paid. The ASU is effective on a prospective basis for annual periods beginning after December 15, 2024. Retrospective application is permitted. Early adoption is also permitted for annual financial statements that have not yet been issued or made available for issuance. The Company is currently evaluating the provisions of this ASU.

INCOME TAXES (Tables)

12 Months Ended

Dec. 31, 2023

Income Tax Disclosure [Abstract]

Components of Income Before Income Tax

The following represent the U.S. and foreign components of income before income tax for the years ended December 31, 2023, 2022 and 2021:


	Year Ended December 31,
	2023		2022		2021
U.S. federal	$	10,420	$	(3,456)	$	(4,389)
Foreign	105,796		70,818		47,444
Income before income taxes	$	116,216	$	67,362	$	43,055

Components of Income Tax Benefit (Expense)

The following represent components of the income tax benefit (expense) for the years ended December 31, 2023, 2022 and 2021:


	Year Ended December 31,
	2023		2022		2021
Current:
U.S. federal	$	(12,757)	$	(479)	$	(91)
U.S. state	(150)		(18)		(2)
Total U.S. current tax benefit (expense)	(12,907)		(497)		(93)
Foreign	(19,696)		(11,139)		(2,195)
Total current tax expense	(32,603)		(11,636)		(2,288)
Deferred:
U.S. federal	7,316		(10,927)		2,089
U.S. state	63		8		-
Total U.S. deferred tax benefit (expense)	7,379		(10,919)		2,089
Foreign	5,860		5,757		65
Total deferred tax benefit	13,239		(5,162)		2,154
Total income tax expense	$	(19,364)	$	(16,798)	$	(134)

Deferred Tax Assets

Tax effects of temporary differences that give rise to significant portions of the Company’s deferred tax assets at December 31, 2023 and 2022 are presented below:


	December 31,
	2023		2022

Deferred tax assets:
Net operating loss carry forwards (offshore)	$	11,499	$	1,456
Net operating loss carry forwards (U.S.) and credit	4,930		1,246
Deferred revenue (offshore)	2,277		1,826
Accruals (U.S.)	3,632		100
Reserves and other (offshore)	4,662		3,655
Stock-based compensation (U.S.)	2,455		2,060
Stock-based compensation (offshore)	4,393		1,229
Lease liability	1,252		414
Total gross deferred tax assets	35,100		11,986
Less: valuation allowance	(11,917)		(1,782)
Total deferred tax assets	23,183		10,204
Deferred tax liabilities:
Fixed assets	(1,325)		(443)
Equity Investments and unrealized gain on short-term investments	(1,587)		(3,059)
Total deferred tax liabilities	(2,912)		(3,502)
Deferred tax assets, net	$	20,271	$	6,702

Effective Income Tax Rate


	Year Ended December 31,
	2023		2022		2021

Effective tax rate reconciliation:
Income tax provision at statutory rate	21.00	%	21.00	%	21.00	%
Stock Compensation	(2.00)		(2.72)		(12.75)
Foreign rate differential	(10.47)		(9.43)		(11.60)
Other permanent difference	0.03		(0.26)		(0.23)
Foreign income taxed in US	7.39		19.86		10.32
Foreign Research Expense	(8.01)		(4.79)		(6.59)
Change in valuation allowance	8.72		1.28		0.16
Total income tax expense	16.66	%	24.94	%	0.31	%

Aggregate Changes in Balance of Gross Unrecognized Tax Benefits


	Year Ended December 31,
	2023		2022		2021

Beginning balance	$	8,448	$	6,066	$	570
Increase of unrecognized tax benefits taken in prior years	199		—		52
Increase of unrecognized tax benefits related to current year	4,379		2,623		5,476
Reductions for tax positions related to prior years	—		(241)		(32)
Ending balance	$	13,026	$	8,448	$	6,066

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)

12 Months Ended

Dec. 31, 2023

Accounting Policies [Abstract]

Basis of Presentation and Principles of Consolidation

Use of Estimates

Management evaluates these estimates and assumptions on a regular basis. Actual results could differ from those estimates and assumptions.

Common Stock Split

Reclassifications

Cash and Cash Equivalents

The following table presents cash and cash equivalents, according to jurisdiction as of December 31, 2023 and 2022:


	December 31,
	2023		2022
United States	$	43,614	$	25,011
Mainland China	70,418		129,695
China Hong Kong	64,057		89,187
Korea	3,934		4,007
Singapore	67		51
Total	$	182,090	$	247,951

The amounts in mainland China do not include short-term and long-term time deposits which totaled $121,342 and $172,448 at December 31, 2023 and 2022, respectively.

Cash held in the U.S. exceeds the Federal Deposit Insurance Corporation (“FDIC”) insurance limits and is subject to risk of loss. No losses have been experienced to date.

For the year ended December 31, 2023, ACM Shanghai paid $19,200 in dividends to ACM Research.

earnings to finance the operations and expenses of the business, and do not expect to distribute earnings or declare or pay any dividends in the foreseeable future.

Amounts held in Korea exceed the Korea Deposit Insurance Corporation (“KDIC”) insurance limits and are subject to risk of loss. No losses have been experienced to date.

There is no additional restriction for the transfer of cash from bank accounts in the U.S., Korea, Singapore, and Hong Kong.

Land Use Right, Net

Inventory consists of raw materials and related goods, work-in-progress, finished goods, and other consumable materials such as spare parts.

Inventory was recorded at the lower of cost or net realizable value at December 31, 2023 and 2022.

•Net realizable value is the estimated selling price, in the ordinary course of business, less estimated costs to complete or dispose.

Property, Plant and Equipment, Net

Estimated useful lives of assets are as follows:


Buildings and plants			30 years
Computer and office equipment			3 to 5 years
Furniture and fixtures			5 years
Leasehold improvements			shorter of lease term or estimated useful life
Electronic equipment			3 to 5 years
Manufacturing equipment			for small to medium-sized equipment, 5 to 10 years; for large equipment, estimated by purchasing department at time of acceptance
Transportation equipment			4 to 5 years

Intangible Assets, Net

Intangible assets consist of purchase software. Assets are valued at cost at the time of acquisition and are amortized over their beneficial periods.

Valuation of Long-Lived Assets

Leases

Revenue Recognition

1.Identify the contract(s) with a customer;

2.Identify the performance obligations in the contract;

3.Determine the transaction price;

4.Allocate the transaction price to the performance obligations in the contract; and

5.Recognize revenue when (or as) the entity satisfies a performance obligation.

Cost of Revenue

Research and Development Costs

Shipping and Handling Costs

Shipping and handling costs, which relate to transportation of products to customer locations, are charged to selling and marketing expense.

Borrowing Costs

Warranty

Government Subsidies

Stock-based Compensation

Income Taxes

Basic and Diluted Net Income per Common Share

Basic and Diluted Net Income per Share of Common Stock

Basic and diluted net income per share of common stock is calculated as follows:


	Year Ended December 31,
	2023		2022		2021
Numerator:
Net income	$	96,852	$	50,564	$	42,921
Less: Net income attributable to non-controlling interests	19,503		11,301		5,164
Net income available to common stockholders, basic	$	77,349	$	39,263	$	37,757
Less: Dilutive effect arising from stock-based awards by ACM Shanghai	1,841		584		108
Net income available to common stockholders, diluted	$	75,508	$	38,679	$	37,649
Weighted average shares outstanding, basic (1)	60,164,670		59,235,975		57,654,708
Effect of dilutive securities	4,705,873		6,105,796		7,702,008
Weighted average shares outstanding, diluted	64,870,543		65,341,771		65,356,716

Net income per share of common stock:
Basic	$	1.29	$	0.66	$	0.65
Diluted	$	1.16	$	0.59	$	0.58

(1)The results for 2021 have been adjusted to reflect the three-for-one stock split effected in the form of a stock dividend in March 2022. See Note 2 for details.

Comprehensive Income (loss)

Statutory Surplus Reserve

Noncontrolling interests

Financial Instruments

Level 1: Valuations based on quoted prices in active markets for identical assets or liabilities with sufficient volume and frequency of transactions.

Operating and Financial Risks

Concentration of Credit Risk

Interest Rate Risk

Liquidity Risk

Country Risk

Foreign Currency Risk and Translation

Recently Adopted Accounting Pronouncements and Recently Issued Accounting Pronouncements Not Yet Adopted

Recently Adopted Accounting Pronouncements

Recently issued accounting pronouncements not yet adopted

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Land Use Rights, Net (Details)	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Right to use land lease term	50 years

LONG-TERM BORROWINGS - Summary of Long Term Borrowings (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Line of Credit Facility [Line Items]
Long-term debt	$ 60,735	$ 21,009
Current portion of long-term borrowings (note 12)	(6,783)	(2,322)
Long-Term borrowings	53,952	18,687
China Merchants Bank
Line of Credit Facility [Line Items]
Long-term debt	13,362	15,265
Bank of China
Line of Credit Facility [Line Items]
Long-term debt	5,013	5,744
Bank of Shanghai
Line of Credit Facility [Line Items]
Long-term debt	14,120	0
CITIC Bank
Line of Credit Facility [Line Items]
Long-term debt	$ 28,240	$ 0

- Definition

Amount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

+ References + Details

LEASES

12 Months Ended

Dec. 31, 2023

Leases [Abstract]

LEASES

The Company leases space under non-cancelable operating leases for several office and manufacturing locations. These leases do not have significant rent escalation holidays, concessions, leasehold improvement incentives, or other build-out clauses. Further, the leases do not contain contingent rent provisions.

Most leases include one or more options to renew. The Company regularly evaluates the renewal options, and when they are reasonably certain of exercise, the Company includes the renewal period in its lease term.

The components of lease expense were as follows:


	Year Ended December 31,
	2023		2022		2021
Operating lease cost	$	3,580	$	2,816	$	2,451
Short-term lease cost	923		786		394
Lease cost	$	4,503	$	3,602	$	2,845

Supplemental cash flow information related to operating leases was as follows for the years ended December 31, 2023, 2022, and 2021:


	Year Ended December 31,
	2023		2022		2021
Operating cash outflow from operating leases	$	3,580	$	2,816	$	2,451


Operating lease right-of-use assets obtained in exchange for new operating lease liabilities			$	8,195					$	1,054					$	1,818

Maturities of lease liabilities for all operating leases were as follows as of December 31, 2023:


	December 31,
2024	$	3,016
2025	1,767
2026	1,207
2027	1,150
2028 and thereafter	595
Total lease payments	$	7,735
Less: Interest	(709)
Present value of lease liabilities	$	7,026

The weighted average remaining lease terms and discount rates for all operating leases were as follows as of December 31, 2023 and 2022:


	December 31,
	2023		2022
Remaining lease term and discount rate:
Weighted average remaining lease term (years)	3.44		2.00
Weighted average discount rate	3.91	%	4.25	%

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Dec. 31, 2023 shares
Trading Arrangements, by Individual
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Sotheara Cheav [Member]
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	On December 13, 2023, Sotheara Cheav, Senior Vice President, Manufacturing of ACM Shanghai, adopted a Rule 10b5-1 trading arrangement, or the Cheav Plan, that is intended to satisfy the affirmative defense of Rule 10b5-1(c) of the Exchange Act. The Cheav Plan allows for the sale of up to 10,000 shares of Class A common stock, at specific market prices, commencing on the later of March 13, 2024 or the third business day following the disclosure of the Issuer’s financial results for the completed fiscal quarter in which the Cheav Plan was adopted, and continuing until (i) all such shares are sold, (ii) December 4, 2024, or (iii) such date that the Cheav Plan is otherwise terminated according to its terms, whichever comes first.
Name	Sotheara Cheav
Title	Senior Vice President, Manufacturing of ACM Shanghai
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	December 13, 2023
Arrangement Duration	266 days
Aggregate Available	10,000