ACM Research (ACMR) 10-Q 7 Nov 24 2024 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2024	Nov. 04, 2024
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2024
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 Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Central Index Key	0001680062
Document Fiscal Year Focus	2024
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q3
Class A Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		57,606,036
Class B Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		5,021,811

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 333,472	$ 182,090
Restricted cash	1,782	1,083
Short-term time deposits (note 2)	20,304	80,524
Short-term investments (note 15)	20,351	21,312
Accounts receivable, net (note 4)	370,589	283,186
Inventories, net (note 5)	628,720	545,395
Prepaid expenses	10,794	20,023
Total current assets	1,445,314	1,176,110
Property, plant and equipment, net (note 6)	250,099	201,848
Land use right, net (note 7)	8,320	8,367
Operating lease right-of-use assets, net (note 11)	5,680	7,026
Intangible assets, net	2,838	2,538
Long-term time deposits (note 2)	13,517	40,818
Deferred tax assets (note 19)	13,400	20,271
Long-term investments (note 14)	33,655	27,880
Other long-term assets (note 8)	21,352	6,050
Total assets	1,794,175	1,490,908
Current liabilities:
Short-term borrowings (note 9)	33,795	31,335
Current portion of long-term borrowings (note 12)	30,670	6,783
Advances from customers (note 3)	215,678	181,368
Deferred revenue (note 3)	10,138	3,687
Income taxes payable (note 19)	6,796	6,401
FIN-48 payable (note 19)	8,991	12,149
Other payables and accrued expenses (note 10)	115,388	102,951
Current portion of operating lease liabilities (note 11)	2,377	2,764
Total current liabilities	610,035	500,659
Long-term borrowings (note 12)	106,069	53,952
Long-term operating lease liabilities (note 11)	3,303	4,262
Other long-term liabilities (note 13)	5,685	5,873
Total liabilities	725,092	564,746
Commitments and contingencies (note 21)
Equity:
Additional paid-in capital	669,540	629,845
Retained earnings	229,374	156,827
Statutory surplus reserve (note 22)	30,060	30,060
Accumulated other comprehensive loss	(40,815)	(49,349)
Total ACM Research, Inc. stockholders’ equity	888,166	767,390
Non-controlling interests	180,917	158,772
Total equity	1,069,083	926,162
Total liabilities and equity	1,794,175	1,490,908
Class A Common Stock
Equity:
Common stock	6	6
Class B Common Stock
Equity:
Common stock	1	1
Related Party
Current assets:
Other receivables	1,453	2,432
Current liabilities:
Accounts payable	15,392	11,407
Nonrelated Party
Current assets:
Other receivables	57,849	40,065
Current liabilities:
Accounts payable	$ 170,810	$ 141,814

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income Statement [Abstract]
Revenue (note 3)	$ 203,976	$ 168,569	$ 558,647	$ 387,402
Cost of revenue, including cost of revenue from related parties of $15,276 and $46,547 for the three and nine months ended September 30, 2024, respectively, and $7,952 and $37,632 for the three and nine months ended September 30, 2023, respectively (note 16)	99,142	80,055	277,908	190,263
Gross profit	104,834	88,514	280,739	197,139
Operating expenses:
Sales and marketing	15,759	16,803	47,067	37,579
Research and development	27,837	26,151	77,723	60,244
General and administrative	17,054	12,387	48,940	26,851
Total operating expenses	60,650	55,341	173,730	124,674
Income from operations	44,184	33,173	107,009	72,465
Interest income	2,967	2,152	7,122	6,283
Interest expense	(1,208)	(640)	(2,923)	(1,984)
Realized gain from sale of short-term investments (note 15)	171	656	444	8,569
Unrealized gain (loss) on short-term investments (note 15)	413	(1,319)	(1,151)	(4,428)
Other income (loss), net	(5,164)	(2,150)	(727)	156
Income (loss) from equity method investments (note 15)	1,316	(160)	101	3,728
Income before income taxes	42,679	31,712	109,875	84,789
Income tax expense (note 19)	(4,007)	(718)	(17,712)	(11,235)
Net income	38,672	30,994	92,163	73,554
Less: Net income attributable to non-controlling interests	7,768	5,315	19,616	13,905
Net income attributable to ACM Research, Inc.	30,904	25,679	72,547	59,649
Comprehensive income:
Net income	38,672	30,994	92,163	73,554
Foreign currency translation adjustment, net of tax	17,089	4,015	10,376	(21,831)
Comprehensive income	55,761	35,009	102,539	51,723
Less: Comprehensive income attributable to non-controlling interests	10,842	7,768	21,458	11,882
Comprehensive income attributable to ACM Research, Inc.	$ 44,919	$ 27,241	$ 81,081	$ 39,841
Net income attributable to ACM Research, Inc. per share of common stock (note 2):
Basic (in dollars per share)	$ 0.49	$ 0.43	$ 1.17	$ 0.99
Diluted (in dollars per share)	$ 0.45	$ 0.39	$ 1.07	$ 0.90
Weighted average shares of common stock outstanding used in computing per share amounts (note 2):
Basic (in shares)	62,500,903	60,219,218	62,017,257	59,953,144
Diluted (in shares)	66,671,526	65,450,941	66,512,143	64,834,051

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Operations and Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Cost of revenue, related party	$ 99,142	$ 80,055	$ 277,908	$ 190,263
Related Party
Cost of revenue, related party	$ 15,276	$ 7,952	$ 46,547	$ 37,632

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock Class A	Common Stock Class B	Common Stock	Common Stock Common Stock Class A	Common Stock Common Stock Class B	Additional Paid- in Capital	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Statutory Surplus Reserve	Accumulated Other Comprehensive Income (Loss)	Non-controlling Interests
Beginning balance (in shares) at Dec. 31, 2022						54,655,286	5,021,811
Beginning 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	73,554								59,649				13,905
Foreign currency translation adjustment	(21,831)											(19,808)	(2,023)
Exercise of stock options (in shares)						919,448
Exercise of stock options	5,290				$ 1			1,455					3,834
Stock-based compensation	14,666							14,666
ACM Shanghai dividend	(3,951)												(3,951)
Ending balance (in shares) at Sep. 30, 2023						55,574,734	5,021,811
Ending balance at Sep. 30, 2023	878,130					$ 6	$ 1	620,210	152,306		16,881	(60,354)	149,080
Beginning balance (in shares) at Jun. 30, 2023						54,951,490	5,021,811
Beginning balance at Jun. 30, 2023	831,775					$ 5	$ 1	608,865	126,627		16,881	(61,916)	141,312
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	30,994								25,679				5,315
Foreign currency translation adjustment	4,015											1,562	2,453
Exercise of stock options (in shares)			623,244			623,244
Exercise of stock options	765				$ 1			764
Stock-based compensation	10,581							10,581
Ending balance (in shares) at Sep. 30, 2023						55,574,734	5,021,811
Ending balance at Sep. 30, 2023	878,130					$ 6	$ 1	620,210	152,306		16,881	(60,354)	149,080
Beginning balance (in shares) at Dec. 31, 2023			56,036,172	5,021,811		56,036,172	5,021,811
Beginning balance at Dec. 31, 2023	926,162					$ 6	$ 1	629,845	156,827		30,060	(49,349)	158,772
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	92,163								72,547				19,616
Foreign currency translation adjustment	10,376											8,534	1,842
Exercise of stock options (in shares)			1,488,347			1,488,347
Exercise of stock options	6,490							5,698					792
Stock-based compensation	40,792							33,997					6,795
ACM Shanghai dividend	(6,900)												(6,900)
Ending balance (in shares) at Sep. 30, 2024			57,524,519	5,021,811		57,524,519	5,021,811
Ending balance at Sep. 30, 2024	1,069,083					$ 6	$ 1	669,540	229,374		30,060	(40,815)	180,917
Beginning balance (in shares) at Jun. 30, 2024						57,402,253	5,021,811
Beginning balance at Jun. 30, 2024	1,001,388					$ 6	$ 1	659,462	198,470		30,060	(54,830)	168,219
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	38,672								30,904				7,768
Foreign currency translation adjustment	17,089											14,015	3,074
Exercise of stock options (in shares)						122,266
Exercise of stock options	53							53
Stock-based compensation	11,881							10,025					1,856
Ending balance (in shares) at Sep. 30, 2024			57,524,519	5,021,811		57,524,519	5,021,811
Ending balance at Sep. 30, 2024	$ 1,069,083					$ 6	$ 1	$ 669,540	$ 229,374		$ 30,060	$ (40,815)	$ 180,917

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Changes in Equity (Parenthetical)	12 Months Ended
	Dec. 31, 2022
Statement of Stockholders' Equity [Abstract]
Accounting Standards Update [Extensible Enumeration]	Accounting Standards Update 2016-13 [Member]

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Cash flows from operating activities:
Net income	$ 92,163	$ 73,554
Adjustments to reconcile net income from operations to net cash generated from (used in) operating activities
Non-cash operating lease cost	2,848	2,639
Depreciation and amortization	7,073	6,021
Loss (gain) on disposals of property, plant and equipment	1,063	(2)
Realized gain on short-term investments	(444)	(8,569)
Income from equity method investments	(101)	(3,728)
Unrealized loss on short-term investments	1,151	4,428
Inventory provision	3,858	5,031
Provision for credit losses	5,796	1,642
Deferred income taxes	6,969	(9,936)
Stock-based compensation	40,792	14,666
Dividends from unconsolidated affiliates	731	5,147
Net changes in operating assets and liabilities:
Accounts receivable	(89,391)	(76,243)
Other receivables	(16,529)	(1,563)
Inventories	(82,201)	(135,888)
Advances to related party (note 16)	979	2,158
Prepaid expenses	9,610	(3,188)
Related party accounts payable (note 16)	3,985	(6,784)
Accounts payable	27,062	39,081
Advances from customers	32,778	42,340
Deferred revenue	6,451	3,753
Income taxes payable	365	7,739
FIN-48 payable	(3,159)	(199)
Other payables and accrued expenses	15,042	6,928
Operating lease liabilities	(2,848)	(2,639)
Other long-term liabilities	(188)	(3,358)
Net cash provided by (used in) operating activities	63,855	(36,970)
Cash flows from investing activities:
Purchase of property and equipment	(71,047)	(49,535)
Purchase of intangible assets	(1,984)	(1,611)
Purchase of short-term investments (note 15)	(1,403)	(18,109)
Purchase of time deposits	(68,810)	(22,930)
Proceeds from redemption and maturity of time deposits	156,015	71,471
Proceeds from sale of short-term investments (note 15)	3,167	19,914
Purchase of long-term investments (note 14)	(7,366)	(6,488)
Net cash provided by (used in) investing activities	8,572	(7,288)
Cash flows from financing activities:
Proceeds from short-term borrowings	32,784	29,314
Repayments of short-term borrowings	(30,738)	(49,730)
Proceeds from long-term borrowings	81,693	27,860
Repayments of long-term borrowings	(6,304)	(1,770)
ACM Shanghai dividend	(6,900)	(3,951)
Proceeds from exercise of stock options	6,490	5,290
Net cash provided by financing activities	77,025	7,013
Effect of exchange rate changes on cash, cash equivalents and restricted cash	2,629	(3,545)
Net increase (decrease) in cash, cash equivalents and restricted cash	152,081	(40,790)
Cash, cash equivalents and restricted cash at beginning of period	183,173	248,451
Cash, cash equivalents and restricted cash at end of period	335,254	207,661
Supplemental disclosure of cash flow information:
Interest paid, net of capitalized interest	2,923	1,984
Cash paid for income taxes	9,799	16,474
Reconciliation of cash, cash equivalents and restricted cash in consolidated statements of cash flows:
Cash and cash equivalents	333,472	207,101
Restricted cash	1,782	560
Cash, cash equivalents and restricted cash	335,254	207,661
Other Noncash Investing and Financing Items [Abstract]
Cashless exercise of stock options	317	211
Transfer from inventory to property, plant and equipment	0	4,379
Purchase property, plant and equipment through accounts payable and other payable	0	27,388
Transfer of prepayment for property to property, plant, and equipment	$ 5,584	$ 0

DESCRIPTION OF BUSINESS

DESCRIPTION OF BUSINESS	9 Months Ended
	Sep. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
DESCRIPTION OF BUSINESS	DESCRIPTION OF BUSINESS ACM Research, Inc. (“ACM” or “ACM Research”) and its subsidiaries (collectively with ACM, the “Company”) develop, manufacture and sell capital equipment to the global semiconductor industry. The Company has direct or i ndirect interests in the follow ing subsidiaries: Effective interest held as at Name of subsidiaries Place and date of incorporation Principal Activities September 30, December 31, ACM Research (Shanghai), Inc. ("ACM Shanghai") Mainland China, May 2005 Principal operating subsidiary 82.0 % 82.1 % ACM Research (Wuxi), Inc. ("ACM Wuxi") Mainland China, July 2011 Sales and services 82.0 % 82.1 % CleanChip Technologies Limited ("CleanChip") Hong Kong, June 2017 Trading partner between ACM Shanghai and its customers 82.0 % 82.1 % ACM Research Korea CO., LTD. Korea, December 2017 Sales, marketing, R&D, production 82.0 % 82.1 % ACM Research ( Lingang), Inc. ("ACM Lingang") (1) Mainland China, March 2019 Management of production activities 82.0 % 82.1 % ACM Research (CA), Inc. ("ACM California") USA, April 2019 Procurement for ACM Shanghai 82.0 % 82.1 % ACM Research (Cayman), Inc. Cayman Islands, April 2019 Administrative function (inactive) 100.0 % 100.0 % ACM Research (Singapore) PTE. Ltd. ("ACM Singapore") Singapore, August 2021 Sales, marketing, business development 100.0 % 100.0 % ACM Research (Beijing), Inc. ("ACM Beijing") Mainland China, February 2022 Sales, marketing, business development 82.0 % 82.1 % Hanguk ACM CO., LTD Korea, March 2022 Sales, services, business development 100.0 % 100.0 % Yusheng Micro Semiconductor (Shanghai) Co., Ltd. Mainland China, June 2023 Business development 82.0 % 82.1 % ACM-Wooil Microelectronics (Shanghai) Co., Ltd. Mainland China, June 2023 Component development and production 59.3 % 59.4 % (1) ACM Research (Lingang) Inc. is the English name referred to by its Chinese language name Shengwei Research (Shanghai), Inc., or ACM Shengwei in prior filings. ACM Research (Lingang), Inc. and Shengwei Research (Shanghai), Inc. refer to the same entity.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation and Principles of Consolidation The Company’s condensed consolidated financial statements include the accounts of ACM and its subsidiaries. ACM’s subsidiaries are those entities in which ACM, directly or indirectly, controls a majority of the voting power. All significant intercompany transactions and balances have been eliminated upon consolidation. The accompanying condensed consolidated financial statements of the Company have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information and the rules and regulations of the Securities and Exchange Commission (the “SEC”) for reporting on Form 10-Q. Accordingly, they do not include all the information and footnotes required by GAAP for complete financial statements. The accompanying condensed consolidated financial statements should be read in conjunction with the historical consolidated financial statements of the Company for the year ended December 31, 2023 included in ACM’s Annual Report on Form 10-K for the fiscal year ended December 31, 2023. The accompanying condensed consolidated financial statements are unaudited. In the opinion of management, these unaudited condensed consolidated financial statements of the Company reflect all adjustments that are necessary for a fair presentation of the Company’s financial position and results of operations. Such adjustments are of a normal recurring nature, unless otherwise noted. The balance sheet as of September 30, 2024 and the results of operations for the three and nine months ended September 30, 2024 are not necessarily indicative of the results to be expected for any future period. 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 investments 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. Cash and Cash Equivalents Cash and cash equivalents consist of cash on hand, 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 September 30, 2024 and December 31, 2023: September 30, December 31, United States $ 59,039 $ 43,614 Mainland China 80,115 70,418 China Hong Kong 190,948 64,057 Korea 3,303 3,934 Singapore 67 67 Total $ 333,472 $ 182,090 The amounts in mainland China do not include short-term and long-term time deposits which in aggregate totaled $33,821 and $121,342 at September 30, 2024 and December 31, 2023, respectively. Cash held in the U.S. exceeds the Federal Deposit Insurance Corporation insurance limits and is subject to risk of loss. No losses have been experienced to date. Cash amounts held 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 restrictions and limitations on its ability to transfer funds to ACM or among our other subsidiaries. However, cash held 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 and ACM Lingang. For these transactions, ACM Shanghai and ACM Lingang make cash payments to ACM California in accordance with applicable transfer pricing arrangements. For the three months ended September 30, 2024 and 2023, cash payments from ACM Shanghai and ACM Lingang to ACM California for the procurement of goods and services was $2,335 and $10,724, respectively. For the nine months ended September 30, 2024 and 2023, cash payments from ACM Shanghai and ACM Lingang to ACM California for the procurement of goods and services was $16,734 and $36,155, 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 advanced payments from customers is repatriated back to ACM Shanghai 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. Amounts held in Korea exceed the Korea Deposit Insurance Corporation insurance limits and is 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. For the nine months ended September 30, 2024 and 2023, with the exception of sales and services-related transfer-pricing payments in the ordinary course of business, and dividend paid by ACM Shang hai to the stockholders of ACM Shanghai (including ACM Research), no transfers, or distributions have been made between ACM Research and its subsidiaries, including ACM Shanghai, or to holders of ACM Research Class A common stock. 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 condensed consolidated financial statements based on their expected time of collection. They are also subject to the risk control regulatory standards described above upon maturity. At September 30, 2024 and December 31, 2023, time deposits consisted of the following: September 30, December 31, Deposit in China Merchant Bank which matured on January 29, 2024 with an annual interest rate of 2.85% $ — $ 29,797 Deposit in Bank of Ningbo which matured on February 17, 2024 with an annual interest rate of 2.85% $ — $ 44,630 Deposit in Shanghai Pudong Development Bank which was redeemed on June 20, 2024 with an annual interest rate of 3.10% $ — $ 7,322 Deposit in Shanghai Pudong Development Bank which was redeemed on May 28, 2024 with an annual interest rate of 3.10% $ — $ 7,307 Deposit in Shanghai Pudong Development Bank which was redeemed on March 7, 2024 with an annual interest rate of 3.10% $ — $ 4,376 Deposit in Shanghai Pudong Development Bank which was redeemed on March 22, 2024 with an annual interest rate of 3.10% $ — $ 4,373 Deposit in Shanghai Pudong Development Bank which was redeemed on January 29, 2024 with an annual interest rate of 3.10% $ — $ 2,912 Deposit in China Industrial Bank which matures on January 30, 2026 with an annual interest rate of 3.15% $ 13,517 $ 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 matured on May 22, 2024 with an annual interest rate of 5.38% $ — $ 3,018 Deposit in China Everbright Bank which matures on January 9, 2025 with an annual interest rate of 5.29% $ 10,116 $ — Deposit in China Everbright Bank which matures on November 23, 2024 with an annual interest rate of 5.28% $ 10,188 $ — Total $ 33,821 $ 121,342 For the three months ended September 30, 2024 and 2023, interest income related to time deposits was $486 and $867, respectively. For the nine months ended September 30, 2024 and 2023, interest income related to time deposits was $1,732 and $2,779, respectively. 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 co ndensed consolidated statements of comprehensive income. 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. 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 September 30, 2024: Assets Cash and cash equivalents $ 32,943 $ — $ — $ 32,943 Short-term investments 20,351 — — 20,351 $ 53,294 $ — $ — $ 53,294 As of December 31, 2023: Assets Cash and cash equivalents $ 37,518 $ — $ — $ 37,518 Short-term investments 21,312 — — 21,312 $ 58,830 $ — $ — $ 58,830 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 September 30, 2024, and the Company did not recognize any unrealized gains (upward adjustments) or unrealized losses (downward adjustments) resulting from observable price changes in orderly transactions for an identical or similar investment of the same issuer for its long-term investments accounted for using measurement alternatives during the three and nine months ended September 30, 2024 and 2023. Refer to Note 12 for fair value information related to the Company’s outstanding long-term borrowings as of September 30, 2024 and December 31, 2023 . Basic and Diluted Net Income per Share of Common Stock Basic and diluted net income per share of common stock are calculated as follows: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Numerator: Net income $ 38,672 $ 30,994 $ 92,163 $ 73,554 Less: Net income attributable to non-controlling interests 7,768 5,315 19,616 13,905 Net income available to common stockholders, basic $ 30,904 $ 25,679 $ 72,547 $ 59,649 Less: Dilutive effect arising from stock-based awards by ACM Shanghai 585 461 1,503 1,338 Net income available to common stockholders, diluted $ 30,319 $ 25,218 $ 71,044 $ 58,311 Weighted average shares outstanding, basic 62,500,903 60,219,218 62,017,257 59,953,144 Effect of dilutive securities 4,170,623 5,231,723 4,494,886 4,880,907 Weighted average shares outstanding, diluted 66,671,526 65,450,941 66,512,143 64,834,051 Net income per share of common stock: Basic $ 0.49 $ 0.43 $ 1.17 $ 0.99 Diluted $ 0.45 $ 0.39 $ 1.07 $ 0.90 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 Research did not have any participating securities outstanding during the three and nine months ended September 30, 2024 and 2023. ACM Research 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 Research did not declare cash dividends during the nine months ended September 30, 2024 or 2023, 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 condensed consolidated statements of comprehensive income 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, such as stock options that could share in ACM Research’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 1,397,590 and 887,985 stock options for the three and nine months ended September 30, 2024, respectively, and 1,757,605 and 4,099,228 stock options for the three and nine months ended September 30, 2023, respectively. 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 and cash equivalents and time deposits with financial institutions that management believes are creditworthy. The Company is potentially subject to concentrations of credit risks in its revenue and accounts receivable. • Revenue concentration. For the three months ended September 30, 2024 and 2023, four customers accounted for 62.3% a nd two customers accounted for 53.2% of revenue, respectively. For the nine months ended September 30, 2024 and 2023, four customers accounted for 56.3% and three customer accounted for 48.8% of revenue, respectively. • Accounts receivable concentration. As of September 30, 2024 and December 31, 2023, three customers accounted for 51.6% and four customers accounted for 59.1%, 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. 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.

REVENUE FROM CONTRACTS WITH CUS

REVENUE FROM CONTRACTS WITH CUSTOMERS	9 Months Ended
	Sep. 30, 2024
Revenue from Contract with Customer [Abstract]
REVENUE FROM CONTRACTS WITH CUSTOMERS	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: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Single Wafer Cleaning, Tahoe and Semi-Critical Cleaning Equipment $ 160,985 $ 132,417 $ 423,676 $ 281,559 ECP (front-end and packaging), Furnace and Other Technologies 34,600 25,508 99,362 71,223 Advanced Packaging (excluding ECP), Services & Spares 8,391 10,644 35,609 34,620 Total Revenue by Product Category $ 203,976 $ 168,569 $ 558,647 $ 387,402 Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Mainland China $ 203,672 $ 168,302 $ 552,642 $ 375,528 Other regions 304 267 6,005 11,874 $ 203,976 $ 168,569 $ 558,647 $ 387,402 Below are the accounts receivables and contract liabilities balances as of: September 30, December 31, Accounts receivable $ 370,589 $ 283,186 Advances from customers 215,678 181,368 Deferred revenue $ 10,138 $ 3,687 During the nine months ended September 30, 2024, advances from customers increased by $34.3 million, due to an increase of payments made by customers for first tools under evaluation, offset by a decrease in customer pre-payments for tools prior to delivery. Below are revenues recognized from amounts included in contract liabilities at the beginning of the year. Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Revenue recognized from amounts included in contract liabilities at the beginning of the year $ 28,077 $ 24,138 $ 114,260 $ 70,023

ACCOUNTS RECEIVABLE

ACCOUNTS RECEIVABLE	9 Months Ended
	Sep. 30, 2024
Receivables [Abstract]
ACCOUNTS RECEIVABLE	ACCOUNTS RECEIVABLE At September 30, 2024 and December 31, 2023, accounts receivable consisted of the following: September 30, December 31, Accounts receivable $ 380,449 $ 288,016 Less: Allowance for credit losses (9,860) (4,830) Total accounts receivable, net $ 370,589 $ 283,186 The $87.4 million increase in accounts receivable, net for the first nine months of 2024 corresponds to a $171.2 million increase in revenue compared to the nine months ended September 30, 2023. The movement of the allowance for credit losses for the nine months ended September 30, 2024 is as follows: Allowance for credit losses, before tax, as of December 31, 2023 Provision for credit losses, net Allowance for credit losses, before tax, as of September 30, 2024 September 30, $ (4,830) (5,030) $ (9,860)

INVENTORIES

INVENTORIES	9 Months Ended
	Sep. 30, 2024
Inventory Disclosure [Abstract]
INVENTORIES	INVENTORIES At September 30, 2024 and December 31, 2023, inventories consisted of the following: September 30, December 31, Raw materials $ 250,326 $ 235,062 Work-in-process 79,469 81,438 Finished goods 298,925 228,895 Total inventory, net $ 628,720 $ 545,395 At September 30, 2024 and December 31, 2023, the value of finished goods inventory of which were first-tools at customer physical locations for which customers were contractually obligated to take ownership upon acceptance totaled $196,987 and $123,390, respectively. The $15,264 increase in raw materials at September 30, 2024 compared to December 31, 2023 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 $70,030 increase in finished goods inventory at September 30, 2024 compared to December 31, 2023 primarily reflects a higher value of first-tools under evaluation by existing or prospective customers, partly offset by a reduction of finished goods inventory at the Company's facilities. 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 a repeat shipment or a first tool shipment. At the end of each period, the Company assesses the status of each item in work-in-process and finished goods. 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.

PROPERTY, PLANT AND EQUIPMENT,

PROPERTY, PLANT AND EQUIPMENT, NET	9 Months Ended
	Sep. 30, 2024
Property, Plant and Equipment [Abstract]
PROPERTY, PLANT AND EQUIPMENT, NET	PROPERTY, PLANT AND EQUIPMENT, NET At September 30, 2024 and December 31, 2023, property, plant and equipment consisted of the following: September 30, December 31, Buildings and plants $ 89,548 $ 83,109 Manufacturing equipment 19,248 16,556 Office equipment 5,896 4,953 Transportation equipment 409 404 Leasehold improvement 8,404 7,889 Total cost 123,505 112,911 Less: Total accumulated depreciation and amortization (23,631) (17,503) Construction in progress 150,225 106,440 Total property, plant and equipment, net $ 250,099 $ 201,848 Depreciation expense for the three months ended September 30, 2024 and 2023 was $2,389 and $2,023, respectively, and $7,073 and $5,077 for the nine months ended September 30, 2024 and 2023, respectively. Buildings and plants represent Lingang housing property owned by ACM Lingang at a value of RMB 249,746 ($35,639), and facilities for the new headquarters of ACM Shanghai ("Zhangjiang New Building") at a value of RMB 377,779 ($53,909), as of September 30, 2024. The Lingang housing property is pledged as security for loans from China Merchants Bank (Note 12). Construction in progress primarily refle cts costs incurred related to the construction of ACM Shanghai’s Lingang development and production center, which is scheduled to begin initial operations

LAND USE RIGHT, NET

LAND USE RIGHT, NET	9 Months Ended
	Sep. 30, 2024
Land Use Right, Net [Abstract]
LAND USE RIGHT, NET	LAND USE RIGHT, NET A summary of land use right is as follows: September 30, December 31, Land use right purchase amount $ 9,092 $ 8,996 Less: accumulated amortization (772) (629) Land use right, net $ 8,320 $ 8,367 The amortization for the three months ended September 30, 2024 and 2023 was $58 and $44, respectively, and the nine months ended September 30, 2024 and 2023 was $143 and $136. The annual amortization of land use right is as follows: Year ending December 31, remainder of 2024 $ 45 2025 182 2026 182 2027 182 2028 182 2029 and thereafter 7,547 Total $ 8,320

OTHER LONG-TERM ASSETS

OTHER LONG-TERM ASSETS	9 Months Ended
	Sep. 30, 2024
Other Assets, Noncurrent Disclosure [Abstract]
OTHER LONG-TERM ASSETS	OTHER LONG-TERM ASSETS At September 30, 2024 and December 31, 2023, other long-term assets consisted of the following: September 30, December 31, Prepayments for property, plant and equipment $ 17,732 $ 3,380 Lease deposits 920 834 Security deposit for land use right 703 696 Others 1,997 1,140 Total other long-term assets $ 21,352 $ 6,050

SHORT-TERM BORROWINGS

SHORT-TERM BORROWINGS	9 Months Ended
	Sep. 30, 2024
Debt Disclosure [Abstract]
SHORT-TERM BORROWINGS	SHORT-TERM BORROWINGS At September 30, 2024 and December 31, 2023, s hort-term borrowings consisted of the following: September 30, December 31, Line of credit up to RMB 150,000 from China Everbright Bank, 1)due on August 29, 2024 with an annual interest rate of 3.00%. - 2,463 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 2)due on March 20, 2025 with an annual interest rate of 2.75%. 17,136 - 3)due on September 22, 2025 with an annual interest rate of 2.50%. 5,711 - 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 18)due on February 27, 2025 with an annual interest rate of 2.60%. 1,356 - 19)due on February 28, 2025 with an annual interest rate of 2.60%. 1,356 - 20)due on March 1, 2025 with an annual interest rate of 2.60%. 1,356 - 21)due on March 5, 2025 with an annual interest rate of 2.60%. 1,357 - 22)due on March 8, 2025 with an annual interest rate of 2.60%. 1,285 - 23)due on August 27, 2025 with an annual interest rate of 2.60%. 1,357 - 24)due on September 11, 2025 with an annual interest rate of 2.60%. 1,357 - 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%. 1,524 1,544 Total $ 33,795 $ 31,335 For the three months ended September 30, 2024 and 2023, interest expense related to short-term borrowings amounted to $373 and $364, respectively, and for the nine months ended September 30, 2024 and 2023, interest expense related to short-term borrowings amounted to $ 1,011 and $ 1,338 , re spectively.

OTHER PAYABLES AND ACCRUED EXPE

OTHER PAYABLES AND ACCRUED EXPENSES	9 Months Ended
	Sep. 30, 2024
Payables and Accruals [Abstract]
OTHER PAYABLES AND ACCRUED EXPENSES	OTHER PAYABLES AND ACCRUED EXPENSES At September 30, 2024 and December 31, 2023, other payables and accrued expenses consisted of the following: September 30, December 31, Accrued commissions $ 20,968 $ 15,572 Accrued warranty 11,877 9,834 Accrued payroll 18,632 14,840 Accrued professional fees 412 696 Accrued machine testing fees 1,710 1,762 Accrued machine sales fees 8,431 6,010 Accrued Lingang construction fees 28,413 33,729 Others 24,945 20,508 Total $ 115,388 $ 102,951 Warranties The Company provides standard warranties on its products. The liability amount is based on actual historical warranty spending activity by type of product, customer, and geographic region, modified for any known differences such as the impact of product reliability improvements. Changes in the Company’s accrued warranty were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Balance at beginning of period $ 11,273 $ 9,179 $ 9,834 $ 8,780 Warranties accrued during the period 3,193 2,386 8,291 5,381 Settlements made during the period (2,589) (1,117) (6,248) (3,713) Balance at end of period $ 11,877 $ 10,448 $ 11,877 $ 10,448

LEASES

LEASES	9 Months Ended
	Sep. 30, 2024
Leases [Abstract]
LEASES	LEASES The Company leases space under non-cancelable operating leases for several offices 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: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Operating lease cost $ 844 $ 899 $ 2,848 $ 2,639 Short-term lease cost 313 267 986 859 Total lease cost $ 1,157 $ 1,166 $ 3,834 $ 3,498 Supplemental cash flow information related to operating leases was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Operating cash outflow from operating leases $ 844 $ 899 $ 2,848 $ 2,639 Operating lease right-of-use assets obtained (removed) in exchange for new (cancelled) operating lease liabilities $ (17) $ (714) $ 604 $ 5,878 As of September 30, 2024, maturities of outstanding lease liabilities for all operating leases were as follows: December 31, remainder of 2024 $ 916 2025 2,139 2026 1,355 2027 1,206 2028 and thereafter 638 Total lease payments $ 6,254 Less: Interest (574) Present value of lease liabilities $ 5,680 The weighted average remaining lease terms and discount rates for all operating leases were as follows: September 30, December 31, Remaining lease term and discount rate: Weighted average remaining lease term (years) 3.17 3.44 Weighted average discount rate 3.85 % 3.91 %

LONG-TERM BORROWINGS

LONG-TERM BORROWINGS	9 Months Ended
	Sep. 30, 2024
Long-Term Debt, by Current and Noncurrent [Abstract]
LONG-TERM BORROWINGS	LONG-TERM BORROWINGS At September 30, 2024 and December 31, 2023, long-term borrowings consisted of the following: September 30, December 31, Loan from China Merchants Bank $ 12,221 $ 13,362 Loans from Agricultural Bank of China 2,771 — Loans from Bank of China 29,129 5,013 Loan from Bank of Shanghai 14,280 14,120 Loans from China CITIC Bank 28,509 28,240 Loan from China Everbright Bank 49,829 — Less: Current portion (30,670) (6,783) Total $ 106,069 $ 53,952 The loan from China Merchants Bank is for the purpose of purchasing housing property in Lingang, Shanghai. The loan is repayable in 120 total installments with the last installment due in November 2030, with an annual interest rate o f 3.95%. The loan is pledged by the property of ACM Lingang and guaranteed by ACM Shanghai. The loan from Agricultural Bank of China is for the purpose of purchasing housing property in Lingang, Shanghai. The loan is repayable in 120 total installments with the last installment due in July 2034, with an annual interest rate of 2.78%. The loan is pledged by the property of ACM Lingang and guaranteed by ACM Shanghai. The second from Agricultural Bank of China is for the purpose of purchasing housing property in Lingang, Shanghai. The loan is repayable in 120 total installments with the last installment due in September 2034, with an annual interest rate of 2.78%. The loan is pledged by the property of ACM Lingang and guaranteed by ACM Shanghai. Two loans from Bank of China are for the purpose of funding ACM Shanghai project expenditures. The first loan bore interest at an annual rate of 2.60% and was repayable in 6 installments with the last installment paid in September 2024. The second loan from Bank of China is for the purpose of funding ACM Shanghai's general corporate expenses and working capital. The loan bears interest at an annual rate of 2.62% and is payable in 6 installments, with the last installment due in June 2027 . 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 3.1% and is 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 d ue in November 2025. The loan from the China Everbright Bank is for the purpose of funding ACM's general corporate expenses and working capital. The loan bears interest at an annual floating rate of 2.60% and is payable in 6 installments, with the last installment due in June 2027. As of September 30, 2024 and December 31, 2023, the total carrying amount of long-term loans w as $136,739 and $60,735, compared with an estimated fair value o f $129,024 and $56,462, 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). Scheduled principal payments for the outstanding long-term loan, including the current portion, as of September 30, 2024 are as follows: Year ending December 31 remainder of 2024 $ 674 2025 44,867 2026 26,073 2027 56,236 2028 2,025 Thereafter 6,864 $ 136,739 For the three months ended September 30, 2024 and 2023, interest expense related to long-term borrowings was $835 and $276, respectively . For the nine months ended September 30, 2024 and 2023, interest expense related to long-term borrowings was $1,912 and $ 646, respectively.

OTHER LONG-TERM LIABILITIES

OTHER LONG-TERM LIABILITIES	9 Months Ended
	Sep. 30, 2024
Other Liabilities Disclosure [Abstract]
OTHER LONG-TERM LIABILITIES	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. At September 30, 2024 and December 31, 2023, other long-term liabilities consisted of the following unearned government subsidies: September 30, 2024 December 31, 2023 Subsidies commenced in 2020 and prior $ 789 $ 1,107 Subsidies to SW Lingang R&D development commenced in 2021 3,486 3,467 Other 1,410 1,299 Total $ 5,685 $ 5,873

LONG-TERM INVESTMENTS

LONG-TERM INVESTMENTS	9 Months Ended
	Sep. 30, 2024
Long-Term Investments [Abstract]
LONG-TERM INVESTMENTS	LONG-TERM INVESTMENTS On January 12, 2024, ACM Shanghai entered into an investment agreement with Company C to invest RMB 12,500 ( $1,760 ), which represented 5.0% of the Company C's total equity interest. Since there is no readily determinable fair value, the Company measures the investments at measurement alternative. On January 19, 2024, ACM Shanghai entered into a limited partnership agreement with Company D to invest RMB 30,000 ( $4,230 ), which represented 16.7% of the partnership's total equity interest. The investment in the limited partnership with Company D is accounted for under the equity method in accordance with ASC323-30-S99-1. On January 22, 2024, ACM Shanghai entered into an investment agreement with Company E to invest RMB 10,000 ($1,403 ) which represented 0.6% of th e Company E's total equity interest. The transaction was closed in April 2024. Since there is no readily determinable fair value, the Company measures the investments at measurement alternative. Equity investee: Initial investment dates Investment entity Percent ownership by ACM and subsidiaries Investment purchase price Ninebell Co., Ltd. ("Ninebell") September 2017 ACM 20.0% $ 1,200 Wooil Flucon Co. ("Wooil") August 2022 ACM Singapore 20.0% $ 1,000 Hefei Shixi Chanheng Integrated Circuit Industry Venture Capital FundPartnership (LP) (“Hefei Shixi”) September 2019 ACM Shanghai 10.0% RMB 30,000 ($4,200) Shengyi Semiconductor Technology Co., Ltd. ("Shengyi") June 2019 ACM Shanghai 14.0% $ 109 Company D February 2024 ACM Shanghai 16.7% RMB 30,000 ($4,230) Investments accounted for using measurement alternative: Waferworks (Shanghai) Co., Ltd. (“Waferworks”) October 2021 ACM Shanghai 0.3% $ 1,568 Shengyi September 2023 ACM Shanghai 1.0% RMB 6,100 ($860) Company A September 2023 ACM Shanghai 4.4% RMB 30,000 ($4,200) Company B November 2023 ACM Shanghai 1.4% RMB 6,600 ($930) Company C February 2024 ACM Shanghai 5.0% RMB 12,500 ($1,760) Company E April 2024 ACM Shanghai 0.6% RMB 10,000 ($1,403) Equity investee: September 30, December 31, Ninebell $ 6,516 $ 5,632 Wooil 944 1,003 Shengyi 2,594 1,693 Hefei Shixi 7,047 9,174 Company D 4,281 — Subtotal 21,382 17,502 Investments accounted for using measurement alternative: Waferworks — 1,412 Shengyi 867 857 Company A 4,281 4,236 Company B 942 932 Company C 1,784 — Company E 1,427 — Other 2,972 2,941 Subtotal measurement alternative 12,273 10,378 Total 33,655 27,880 For the three months ended September 30, 2024 and 2023, the Company’s share of equity investees’ net income (loss) was $1,316 and $(160), respectively, and $101 and $3,728 for the nine months ended September 30, 2024 and 2023, respectively, which amounts were included in income (loss) from equity method investments in the accompanying condensed consolidated statements of comprehensive income. For the three months ended September 30, 2024 and 2023, the Company received $131 and $52 dividends from equity investee. For the nine months ended September 30, 2024 and 2023, the Company received $731 and $5,147 dividends from equity investee.

SHORT-TERM INVESTMENTS

SHORT-TERM INVESTMENTS	9 Months Ended
	Sep. 30, 2024
Investments, Debt and Equity Securities [Abstract]
SHORT-TERM INVESTMENTS	SHORT-TERM INVESTMENTS 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. The limited partners of the Nuode Asset Fund contributed a total RMB 160 million ($22,160) to the fund, of which ACM Shanghai contributed RMB 30 million ($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, and was apportioned to the limited partners in proportion to their respective capital contributions . The investments were fully-disposed by Nuode Asset Fund during the three months ended June 30, 2024. The Company received net proceeds of RMB 22,478 ($3,167) during the three months ended September 30, 2024. Pursuant to a Share Purchase Agreement dated June 2023, ACM Shanghai acquired shares of Huahong Semiconductor Limited (“Huahong”) in July 2023 with amount of RMB 100 million ($13,930). The shares held by ACM Shanghai are restricted for sale for a minimum period of twelve months. Huahong completed its 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 30 million ($4,179). The shares held by ACM Shanghai are restricted for sale for a minimum period of twelve months. Zhongjuxin completed its STAR IPO in September 2023. Pursuant to a Share Purchase Agreement dated January 2024, ACM Shanghai acquired shares of Shanghai Syncrystalline Silicon Materials Co., Ltd. (“Syncrystalline”) in February 2024 with amount of RMB 10 million ( $1,409 ). The shares held by ACM Shanghai are restricted for sale for a minimum period of twelve months. Syncrystalline completed its STAR IPO in February 2024. As of September 30, 2024, the Company's total investment costs in Syncrystalline were RMB 20,000 ($2,818), including RMB 10 million ( $1,409 ) invested by ACM Shanghai in 2021 and RMB 10 million ($1,409) invested by ACM Shanghai in February 2024. At September 30, 2024 and December 31, 2023, the components of short-term investments were as follows: September 30, December 31, Short-term investments listed in Shanghai Stock Exchange Cost $ 21,045 $ 20,155 Market value 20,351 21,312 For the three and nine months ended September 30, 2024 and 2023, the net gains (losses) recognized on equity securities were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Unrealized gains (losses) recognized during the reporting period on short-term investment still held at September 30 $ 413 $ (1,319) $ (1,151) $ (4,428) Net gains recognized during the period on short-term sold during the period $ 171 $ 656 $ 444 $ 8,569 Total net gains (losses) recognized at September 30 on short-term investment $ 584 $ (663) $ (707) $ 4,141 For the three and nine months ended September 30, 2024, the Company received proceeds of $3,167 and $3,167 from t he sale of short-term investments, respectively, including realized gains of $171 and $444, respectively . For the three and nine months ended September 30, 2023, the Company received $2,205 and $19,914 in proceeds from the sale of short-term investments, respectively, including realized gains of $656 and $8,569, respectively.

RELATED PARTY BALANCES AND TRAN

RELATED PARTY BALANCES AND TRANSACTIONS	9 Months Ended
	Sep. 30, 2024
Related Party Transactions [Abstract]
RELATED PARTY BALANCES AND TRANSACTIONS	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 condensed consolidated statements of comprehensive income. 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 reflect related party transactions in our condensed consolidated financial statements: Advances to related party September 30, December 31, Ninebell $ 1,453 $ 2,432 Accounts payable September 30, December 31, Ninebell $ 10,042 $ 7,624 Shengyi 5,350 3,783 Total $ 15,392 $ 11,407 Three Months Ended September 30, Nine Months Ended September 30, Purchase of materials 2024 2023 2024 2023 Ninebell $ 13,791 $ 6,830 $ 41,721 $ 33,831 Shengyi 1,485 1,122 4,826 3,801 Total $ 15,276 $ 7,952 $ 46,547 $ 37,632 Three Months Ended September 30, Nine Months Ended September 30, Service fee charged by 2024 2023 2024 2023 Shengyi $ 125 $ 79 $ 352 $ 809

COMMON STOCK

COMMON STOCK	9 Months Ended
	Sep. 30, 2024
Equity [Abstract]
COMMON STOCK	COMMON STOCK ACM is 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 of ACM unless such Board of Directors declares different dividends to the Class A common stock and Class B common stock, which is subject to approval from a majority of common stockholders. During the three months ended September 30, 2024, ACM issued 122,266 shares of Class A common stock upon option exercises by employees and non-employees. During the nine months ended September 30, 2024, ACM issued 1,488,347 shares of Class A common stock upon option exercises by employees and non-employees. During the three months ended September 30, 2023, ACM issued 623,244 shares of Class A common stock upon option exercises by employees and non-employees. During the nine months ended September 30, 2023, ACM issued 919,448 sha res of Class A common stock upon option exercises by employees and non-employees At September 30, 2024 and December 31, 2023, the number of shares of Class A common stock issued and outs tanding wa s 57,524,519 and 56,036,172, respectively. At September 30, 2024 and December 31, 2023, the number of shares of Class B common stock issued and outstanding was 5,021,811 and 5,021,811, respectively.

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	9 Months Ended
	Sep. 30, 2024
Share-Based Payment Arrangement [Abstract]
STOCK-BASED COMPENSATION	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 a service period condition and certain performance conditions 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 option s 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 Company’s employee share option activities during the nine months ended September 30, 2024: Number of Weighted Weighted Weighted Average Outstanding at December 31, 2023 9,998,637 $ 5.15 $ 9.47 6.17 years Granted 460,500 15.31 20.69 Exercised (1,220,340) 2.25 4.81 Forfeited/cancelled (64,288) 12.04 25.43 Outstanding at September 30, 2024 9,174,509 $ 6.00 $ 10.54 5.90 years Vested and exercisable at September 30, 2024 5,656,683 As of September 30, 2024, $25,929 of total unrecognized employee stock-based compensation expense, net of estimated forfeitures, related to employee stock-based awards for ACM were expected to be recognized over a weighted-average period of 3.5 years, after September 30, 2024. Total recognized compensation cost may be adjusted for future changes in estimated forfeitures. The aggregate intrinsic value of options exercised in the three and nine months ended September 30, 2024 w as $234 and $29,311. The aggregate intrinsic value of options outstanding and exercisable as of September 30, 2024 were $96,975 and $72,321, respectively. The fair value of options granted to employees is estimated on the grant date using the Black-Scholes valuation with following assumptions: Nine Months Ended Fair value of share of common stock(1) $23.02-$31.92 Expected term in years(2) 5.81-6.25 Volatility(3) 84.87%-85.48% Risk-free interest rate(4) 4.23%-4.49% Expected dividend(5) —% (1) Fair value of Class A common stock value was 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 Awards The following table summarizes the Company’s non-employee share option activities during the nine months ended September 30, 2024: Number of Weighted Weighted Weighted Outstanding at December 31, 2023 1,170,795 $ 0.42 $ 1.31 2.66 years Exercised (268,007) 0.22 0.50 Forfeited/cancelled (5,878) 0.22 0.50 Outstanding at September 30, 2024 896,910 $ 0.48 $ 1.56 2.51 years Vested and exercisable at September 30, 2024 896,910 As of September 30, 2024 there is no unrecognized non-employee stock-based compensation expense, net of estimated forfeitures, related to stock-based awards expected to be recognized. Total recognized compensation cost may be adjusted for future changes in estimated forfeitures. The aggregate intrinsic value of options exercised in the three and nine months ended September 30, 2 024 was $2,247 and $6,514, respectively. The aggregate intrinsic value of options outstanding and exercisable as of September 30, 2024 was $16,809 . 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, and employees of options to purchase shares of ACM Shanghai’s common stock. The following table summarizes the stock option activities of the ACM Shanghai 2019 Subsidiary Stock Option Plan during the nine months ended September 30, 2024: Number of Weighted Weighted Weighted Outstanding at December 31, 2023 3,134,883 $ 0.24 $ 1.85 0.85 years Exercised (446,154) $ 0.20 $ 1.85 Forfeited/cancelled (92,308) 0.22 $ 1.85 Outstanding at September 30, 2024 2,596,421 $ 0.20 $ 1.85 0.51 years Vested and exercisable at September 30, 2024 2,596,421 The aggregate intrinsic value of options exercised in the three and nine months ended September 30, 2024 was $$0 and $5,198 . The aggregate intrinsic value of options outstanding and exercisable as of September 30, 2024 was $33,788. 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, and 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 three months ended September 30, 2024: Number of Option Shares in ACM Shanghai Weighted Weighted Weighted Outstanding at December 31, 2023 10,575,500 $ 9.49 $ 7.06 3.09 years Granted 1,391,000 $ 6.04 $ 7.00 Forfeited/cancelled (293,065) $ 9.09 $ 7.06 Outstanding at September 30, 2024 11,673,435 $ 9.01 $ 7.00 2.45 years Vested and exercisable at September 30, 2024 - The fair value of options granted to employees is estimated on the grant date using the Black-Scholes valuation with following assumptions: Nine Months Ended September 30, 2024 Fair value of share of common stock (1) $4.93-$6.89 Expected term in years (2) 1.50-4.50 Volatility (3) 45.92%-56.18% Risk-free interest rate (4) 1.50%-2.75% Expected dividend (5) —% (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 Shanghai 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. (5) Expected dividend is assumed to be 0% as the impact is adjusted on the value of share of common stock. As of September 30, 2024, there is $50,887 unrecognized non-employee stock-based compensation expense, net of estimated forfeitures, related to ACM Shanghai stock-based awards expected to be recognized over a weighted-average period of 1.5 years. Total recognized compensation cost may be adjusted for future changes in estimated forfeitures. The aggregate intrinsic value of options exercised in the three and nine months ended September 30, 2024 was $0 as there were no options exercised during the periods. As there were no options exercisable during the periods, t he aggregate intrinsic value of options outstanding and exercisable as of September 30, 2024 were $91,501 and $0, respectively. The following table summarizes the components of stock-based compensation expense included in the condensed consolidated statements of comprehensive income: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Stock-Based Compensation Expense: Cost of revenue $ 447 $ 588 $ 2,020 $ 838 Sales and marketing expense 2,594 2,543 8,645 3,405 Research and development expense 3,373 3,421 12,082 4,831 General and administrative expense 5,467 4,029 18,045 5,592 $ 11,881 $ 10,581 $ 40,792 $ 14,666 Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Stock-based compensation expense by type: Employee stock purchase plan $ 2,860 $ 2,352 $ 7,602 $ 6,345 Non-employee stock purchase plan 21 12 30 35 2019 and 2023 Subsidiary option grants 9,000 8,217 33,160 8,286 $ 11,881 $ 10,581 $ 40,792 $ 14,666

INCOME TAXES

INCOME TAXES	9 Months Ended
	Sep. 30, 2024
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carry-forwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period during which such rates are enacted. 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. As of each reporting date, management considers new evidence, both positive and negative, that could affect its view of the future realization of deferred tax assets. Prior to September 30, 2019, the Company had recorded a valuation allowance for the full amount of net deferred tax assets in the United States, as the realization of deferred tax assets was uncertain. Since September 30, 2019, the Company has not maintained a valuation allowance except for a partial valuation allowance on certain U.S. and foreign deferred tax assets. In order to recognize the remaining U.S. deferred tax assets that continue to be subject to a valuation allowance, the Company will need to generate sufficient U.S. taxable income in future periods before the expiration of the deferred tax assets governed by the tax code. ACM Shanghai has shown a three-year historical cumulative profit and has projections of future income. As a result, the Company does not maintain a valuation allowance. The Company accounts for uncertain tax positions in accordance with the authoritative guidance on income taxes under which the Company may only recognize or continue to recognize tax positions that meet a more likely than not threshold. The Company recognizes accrued interest and penalties related to unrecognized tax benefits as a component of the provision for income taxes. The Company’s effective tax rate differs from statutory rates of 21% for U.S. federal income tax purposes and 15% to 25% for Chinese income tax purposes due to the effects of the valuation allowance and certain permanent differences from book-tax differences, including stock based compensation, deemed dividend income under Subchapter F of the U.S. Internal Revenue Code of 1986, as amended (Subpart F), and global intangible low-taxed income (GILTI) inclusions, and R&D super deduction. As a result, the Company recorded income tax expense of $17,712 and $11,235 during the nine months ended September 30, 2024 and 2023, respectively. The increase in the Company's effective income tax rate for the nine months ended September 30, 2024 compared to the same period of the prior year was primarily due to a decrease in certain discrete tax benefits. Under the change in Section 174 made by the Tax Cuts and Jobs Act of 2017 which became effective on January 1, 2022, 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 results in a significant increase in the Company’s global intangible low-taxed income inclusion. The Company had total unrecognized tax benefits of $7,600 and $13,026 as of September 30, 2024 and December 31, 2023. If recognized, the net impact to effective rate would be $7,518. The Company did not expect any reversal of unrecognized tax benefits in the next 12 months. The Company will recognize interest and penalties, when they occur, related to uncertain tax provisions as a component of tax expense. For the nine months ended September 30, 2024 and 2023, $995 a nd $569 of interest and penalties was recognized, respectively. 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’s four principal mainland China subsidiaries, ACM Shanghai, ACM Wuxi, ACM Beijing and ACM Lingang, are liable for mainland China corporate income taxes at the rates of 15%, 25%, 25% and 15%, respectively. Pursuant to the Corporate Income Tax Law of mainland China, ACM’s mainland China subsidiaries generally would be liable for mainland China corporate income taxes as a rate of 25%. 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, with an effective period of three years and is expected to be re-certified for future years in 2024. In 2021, 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. Income tax expense was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Total income tax expense $ (4,007) $ (718) $ (17,712) $ (11,235)

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies The Company leases offices 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 September 30, 2024, the Company had $11,023 of open capital commitments to construction contracts and had additional $16,737 of capital investment commitments to Ninebell in April 2024. 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 Lingang’s Grant Contract for State-owned Constructio n 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 Lingang pay liquidated damages in the event that within 7 years after the land use right is obtained, or prior to July 9, 2027, 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. 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 and expects that it will meet the milestone in 2024. The Company cannot guarantee that ACM Lingang will achieve the 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 un-estimable damages. The Company’s management has evaluated all such proceedings and claims that existed as of September 30, 2024 and December 31, 2023. In the opinion of management, no provision for liability nor disclosure was required as of September 30, 2024 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 September 30, 2024, the Company had no outstanding legal proceedings.

SEGMENT INFORMATION

SEGMENT INFORMATION	9 Months Ended
	Sep. 30, 2024
Segment Reporting [Abstract]
SEGMENT INFORMATION	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, land use right, 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 periods ended were as follows: September 30, December 31, Long-lived assets by geography: Mainland China $ 263,930 $ 209,725 Korea 12,497 12,190 United States 9,024 1,276 Total $ 285,451 $ 223,191

STATUTORY SURPLUS RESERVE

STATUTORY SURPLUS RESERVE	9 Months Ended
	Sep. 30, 2024
STATUTORY SURPLUS RESERVE [Abstract]
STATUTORY SURPLUS RESERVE	STATUTORY SURPLUS RESERVE In accordance with mainland China’s Foreign Enterprise Law, ACM Shanghai, ACM Lingang, and ACM Wuxi are required to make appropriation to reserve funds, comprising the statutory surplus reserve and discretionary surplus reserve, based on after-tax net income in accordance with generally accepted accounting principles of mainland China (“mainland China GAAP”). Appropriations to the statutory surplus reserve are required to be at least 10% of the after-tax net income determined in accordance with mainland China GAAP until the reserve is equal to 50% of the entities’ registered capital. The amount is calculated annually at the end of each calendar year. The balances of statutory reserve funds was $30,060 as of both September 30, 2024 and December 31, 2023, and is presented as statutory surplus reserve on the Company’s condensed consolidated balance sheets.

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	9 Months Ended
	Sep. 30, 2024
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS On October 1, 2024, the Company acquired a commercial facility, comprised of 39,500 square foot total floor space and which includes a 5,200 square foot functional clean room, for a price of $7.75 million. This facility is located in the City of Hillsboro in Oregon, and is intended to further expand ACM’s R&D and demonstration capability in the U.S. market. ACM Shanghai completed the purchase of additional equity interest of Ninebell (note 16) on October 21, 2024 for the purchase of $16,737. After the purchase, the Company owned 36.4% of Ninebell.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Pay vs Performance Disclosure
Net Income (Loss) Attributable to Parent	$ 30,904	$ 25,679	$ 72,547	$ 59,649

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended	9 Months Ended
	Sep. 30, 2024 shares	Sep. 30, 2024 shares
Trading Arrangements, by Individual
Non-Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Terminated	false
Sotheara Cheav [Member]
Trading Arrangements, by Individual
Material Terms of Trading Arrangement		On August 13, 2024, Sotheara Cheav, Senior Vice President, Manufacturing of ACM Shanghai, adopted a Rule 10b5-1 trading arrangement (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 contemporaneous exercise of options and sale of up to 22,598 shares of Class A Common Stock, at specific market prices, commencing on November 13, 2024, and continuing until (i) all such options are exercised and the underlying shares are sold, (ii) March 31, 2025, 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	August 13, 2024
Expiration Date	March 31, 2025
Arrangement Duration	138 days
Aggregate Available	22,598	22,598
David Wang [Member]
Trading Arrangements, by Individual
Material Terms of Trading Arrangement		On August 13, 2024, David Wang, President, Chief Executive Officer and a member of the Board of Directors of ACM Research, amended a prior Rule 10b5-1 trading arrangement which was entered into on May 14, 2024, and is considered to have terminated such prior Rule 10b5-1 trading arrangement and established a new Rule 10b5-1 trading arrangement (the “Wang Plan”). The Wang Plan allows for the contemporaneous exercise of options and sale of up to 300,000 shares of Class A Common Stock, at specific market prices, commencing on November 22, 2024, and continuing until (i) all such options are exercised and the underlying shares are sold, (ii) April 30, 2025, or (iii) such date that the Wang Plan is otherwise terminated according to its terms, whichever comes first.
August 2024 Trading Arrangement [Member] | David Wang [Member]
Trading Arrangements, by Individual
Name	David Wang
Title	President, Chief Executive Officer and a member of the Board of Directors of ACM Research
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	August 13, 2024
Expiration Date	April 30, 2025
Arrangement Duration	159 days
Aggregate Available	300,000	300,000
May 2024 Trading Arrangement [Member] | David Wang [Member]
Trading Arrangements, by Individual
Name	David Wang
Title	President, Chief Executive Officer and a member of the Board of Directors of ACM Research
Rule 10b5-1 Arrangement Terminated	true
Termination Date	August 13, 2024

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation The Company’s condensed consolidated financial statements include the accounts of ACM and its subsidiaries. ACM’s subsidiaries are those entities in which ACM, directly or indirectly, controls a majority of the voting power. All significant intercompany transactions and balances have been eliminated upon consolidation. The accompanying condensed consolidated financial statements of the Company have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information and the rules and regulations of the Securities and Exchange Commission (the “SEC”) for reporting on Form 10-Q. Accordingly, they do not include all the information and footnotes required by GAAP for complete financial statements. The accompanying condensed consolidated financial statements should be read in conjunction with the historical consolidated financial statements of the Company for the year ended December 31, 2023 included in ACM’s Annual Report on Form 10-K for the fiscal year ended December 31, 2023. The accompanying condensed consolidated financial statements are unaudited. In the opinion of management, these unaudited condensed consolidated financial statements of the Company reflect all adjustments that are necessary for a fair presentation of the Company’s financial position and results of operations. Such adjustments are of a normal recurring nature, unless otherwise noted. The balance sheet as of September 30, 2024 and the results of operations for the three and nine months ended September 30, 2024 are not necessarily indicative of the results to be expected for any future period.
Use of Estimates	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 investments 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.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents consist of cash on hand, 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. Cash held in the U.S. exceeds the Federal Deposit Insurance Corporation insurance limits and is subject to risk of loss. No losses have been experienced to date. Cash amounts held 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 restrictions and limitations on its ability to transfer funds to ACM or among our other subsidiaries. However, cash held in mainland China does exceed applicable insurance limits and is subject to risk of loss, although no such losses have been experienced to date.
Time Deposits	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 condensed consolidated financial statements based on their expected time of collection. They are also subject to the risk control regulatory standards described above upon maturity.
Financial Instruments	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 co ndensed consolidated statements of comprehensive income. 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. 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. The Company did not have any assets and liabilities measured at fair value on a non-recurring basis as of September 30, 2024, and the Company did not recognize any unrealized gains (upward adjustments) or unrealized losses (downward adjustments) resulting from observable price changes in orderly transactions for an identical or similar investment of the same issuer for its long-term investments accounted for using measurement alternatives during the three and nine months ended September 30, 2024 and 2023.
Basic and Diluted Net Income per Share of Common Stock	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 Research did not have any participating securities outstanding during the three and nine months ended September 30, 2024 and 2023. ACM Research 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 Research did not declare cash dividends during the nine months ended September 30, 2024 or 2023, 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 condensed consolidated statements of comprehensive income 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, such as stock options that could share in ACM Research’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 1,397,590 and 887,985 stock options for the three and nine months ended September 30, 2024, respectively, and 1,757,605 and 4,099,228 stock options for the three and nine months ended September 30, 2023, respectively.
Concentration of Credit Risk	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 and cash equivalents and time deposits with financial institutions that management believes are creditworthy.
Recently issued accounting pronouncements not yet adopted	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.

DESCRIPTION OF BUSINESS (Tables

DESCRIPTION OF BUSINESS (Tables)	9 Months Ended
	Sep. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Direct or Indirect Interests of Subsidiaries	The Company has direct or i ndirect interests in the follow ing subsidiaries: Effective interest held as at Name of subsidiaries Place and date of incorporation Principal Activities September 30, December 31, ACM Research (Shanghai), Inc. ("ACM Shanghai") Mainland China, May 2005 Principal operating subsidiary 82.0 % 82.1 % ACM Research (Wuxi), Inc. ("ACM Wuxi") Mainland China, July 2011 Sales and services 82.0 % 82.1 % CleanChip Technologies Limited ("CleanChip") Hong Kong, June 2017 Trading partner between ACM Shanghai and its customers 82.0 % 82.1 % ACM Research Korea CO., LTD. Korea, December 2017 Sales, marketing, R&D, production 82.0 % 82.1 % ACM Research ( Lingang), Inc. ("ACM Lingang") (1) Mainland China, March 2019 Management of production activities 82.0 % 82.1 % ACM Research (CA), Inc. ("ACM California") USA, April 2019 Procurement for ACM Shanghai 82.0 % 82.1 % ACM Research (Cayman), Inc. Cayman Islands, April 2019 Administrative function (inactive) 100.0 % 100.0 % ACM Research (Singapore) PTE. Ltd. ("ACM Singapore") Singapore, August 2021 Sales, marketing, business development 100.0 % 100.0 % ACM Research (Beijing), Inc. ("ACM Beijing") Mainland China, February 2022 Sales, marketing, business development 82.0 % 82.1 % Hanguk ACM CO., LTD Korea, March 2022 Sales, services, business development 100.0 % 100.0 % Yusheng Micro Semiconductor (Shanghai) Co., Ltd. Mainland China, June 2023 Business development 82.0 % 82.1 % ACM-Wooil Microelectronics (Shanghai) Co., Ltd. Mainland China, June 2023 Component development and production 59.3 % 59.4 % (1) ACM Research (Lingang) Inc. is the English name referred to by its Chinese language name Shengwei Research (Shanghai), Inc., or ACM Shengwei in prior filings. ACM Research (Lingang), Inc. and Shengwei Research (Shanghai), Inc. refer to the same entity.

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Cash and Cash Equivalents	The following table presents cash and cash equivalents, according to jurisdiction as of September 30, 2024 and December 31, 2023: September 30, December 31, United States $ 59,039 $ 43,614 Mainland China 80,115 70,418 China Hong Kong 190,948 64,057 Korea 3,303 3,934 Singapore 67 67 Total $ 333,472 $ 182,090
Summary of Time Deposits	At September 30, 2024 and December 31, 2023, time deposits consisted of the following: September 30, December 31, Deposit in China Merchant Bank which matured on January 29, 2024 with an annual interest rate of 2.85% $ — $ 29,797 Deposit in Bank of Ningbo which matured on February 17, 2024 with an annual interest rate of 2.85% $ — $ 44,630 Deposit in Shanghai Pudong Development Bank which was redeemed on June 20, 2024 with an annual interest rate of 3.10% $ — $ 7,322 Deposit in Shanghai Pudong Development Bank which was redeemed on May 28, 2024 with an annual interest rate of 3.10% $ — $ 7,307 Deposit in Shanghai Pudong Development Bank which was redeemed on March 7, 2024 with an annual interest rate of 3.10% $ — $ 4,376 Deposit in Shanghai Pudong Development Bank which was redeemed on March 22, 2024 with an annual interest rate of 3.10% $ — $ 4,373 Deposit in Shanghai Pudong Development Bank which was redeemed on January 29, 2024 with an annual interest rate of 3.10% $ — $ 2,912 Deposit in China Industrial Bank which matures on January 30, 2026 with an annual interest rate of 3.15% $ 13,517 $ 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 matured on May 22, 2024 with an annual interest rate of 5.38% $ — $ 3,018 Deposit in China Everbright Bank which matures on January 9, 2025 with an annual interest rate of 5.29% $ 10,116 $ — Deposit in China Everbright Bank which matures on November 23, 2024 with an annual interest rate of 5.28% $ 10,188 $ — Total $ 33,821 $ 121,342
Fair Value, by Balance Sheet Grouping	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 September 30, 2024: Assets Cash and cash equivalents $ 32,943 $ — $ — $ 32,943 Short-term investments 20,351 — — 20,351 $ 53,294 $ — $ — $ 53,294 As of December 31, 2023: Assets Cash and cash equivalents $ 37,518 $ — $ — $ 37,518 Short-term investments 21,312 — — 21,312 $ 58,830 $ — $ — $ 58,830 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
Basic and Diluted Net Income per Common Share	Basic and diluted net income per share of common stock are calculated as follows: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Numerator: Net income $ 38,672 $ 30,994 $ 92,163 $ 73,554 Less: Net income attributable to non-controlling interests 7,768 5,315 19,616 13,905 Net income available to common stockholders, basic $ 30,904 $ 25,679 $ 72,547 $ 59,649 Less: Dilutive effect arising from stock-based awards by ACM Shanghai 585 461 1,503 1,338 Net income available to common stockholders, diluted $ 30,319 $ 25,218 $ 71,044 $ 58,311 Weighted average shares outstanding, basic 62,500,903 60,219,218 62,017,257 59,953,144 Effect of dilutive securities 4,170,623 5,231,723 4,494,886 4,880,907 Weighted average shares outstanding, diluted 66,671,526 65,450,941 66,512,143 64,834,051 Net income per share of common stock: Basic $ 0.49 $ 0.43 $ 1.17 $ 0.99 Diluted $ 0.45 $ 0.39 $ 1.07 $ 0.90

REVENUE FROM CONTRACTS WITH C_2

REVENUE FROM CONTRACTS WITH CUSTOMERS (Tables)	9 Months Ended
	Sep. 30, 2024
Revenue from Contract with Customer [Abstract]
Disaggregated Revenue Information	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: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Single Wafer Cleaning, Tahoe and Semi-Critical Cleaning Equipment $ 160,985 $ 132,417 $ 423,676 $ 281,559 ECP (front-end and packaging), Furnace and Other Technologies 34,600 25,508 99,362 71,223 Advanced Packaging (excluding ECP), Services & Spares 8,391 10,644 35,609 34,620 Total Revenue by Product Category $ 203,976 $ 168,569 $ 558,647 $ 387,402 Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Mainland China $ 203,672 $ 168,302 $ 552,642 $ 375,528 Other regions 304 267 6,005 11,874 $ 203,976 $ 168,569 $ 558,647 $ 387,402
Accounts Receivables and Contract Liabilities	Below are the accounts receivables and contract liabilities balances as of: September 30, December 31, Accounts receivable $ 370,589 $ 283,186 Advances from customers 215,678 181,368 Deferred revenue $ 10,138 $ 3,687 Below are revenues recognized from amounts included in contract liabilities at the beginning of the year. Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Revenue recognized from amounts included in contract liabilities at the beginning of the year $ 28,077 $ 24,138 $ 114,260 $ 70,023

ACCOUNTS RECEIVABLE (Tables)

ACCOUNTS RECEIVABLE (Tables)	9 Months Ended
	Sep. 30, 2024
Receivables [Abstract]
Accounts Receivable	At September 30, 2024 and December 31, 2023, accounts receivable consisted of the following: September 30, December 31, Accounts receivable $ 380,449 $ 288,016 Less: Allowance for credit losses (9,860) (4,830) Total accounts receivable, net $ 370,589 $ 283,186 The movement of the allowance for credit losses for the nine months ended September 30, 2024 is as follows: Allowance for credit losses, before tax, as of December 31, 2023 Provision for credit losses, net Allowance for credit losses, before tax, as of September 30, 2024 September 30, $ (4,830) (5,030) $ (9,860)

INVENTORIES (Tables)

INVENTORIES (Tables)	9 Months Ended
	Sep. 30, 2024
Inventory Disclosure [Abstract]
Inventories	At September 30, 2024 and December 31, 2023, inventories consisted of the following: September 30, December 31, Raw materials $ 250,326 $ 235,062 Work-in-process 79,469 81,438 Finished goods 298,925 228,895 Total inventory, net $ 628,720 $ 545,395

PROPERTY, PLANT AND EQUIPMENT_2

PROPERTY, PLANT AND EQUIPMENT, NET (Tables)	9 Months Ended
	Sep. 30, 2024
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	At September 30, 2024 and December 31, 2023, property, plant and equipment consisted of the following: September 30, December 31, Buildings and plants $ 89,548 $ 83,109 Manufacturing equipment 19,248 16,556 Office equipment 5,896 4,953 Transportation equipment 409 404 Leasehold improvement 8,404 7,889 Total cost 123,505 112,911 Less: Total accumulated depreciation and amortization (23,631) (17,503) Construction in progress 150,225 106,440 Total property, plant and equipment, net $ 250,099 $ 201,848

LAND USE RIGHT, NET (Tables)

LAND USE RIGHT, NET (Tables)	9 Months Ended
	Sep. 30, 2024
Land Use Right, Net [Abstract]
Land Use Rights	A summary of land use right is as follows: September 30, December 31, Land use right purchase amount $ 9,092 $ 8,996 Less: accumulated amortization (772) (629) Land use right, net $ 8,320 $ 8,367
Annual Amortization of Land Use Right	The annual amortization of land use right is as follows: Year ending December 31, remainder of 2024 $ 45 2025 182 2026 182 2027 182 2028 182 2029 and thereafter 7,547 Total $ 8,320

OTHER LONG-TERM ASSETS (Tables)

OTHER LONG-TERM ASSETS (Tables)	9 Months Ended
	Sep. 30, 2024
Other Assets, Noncurrent Disclosure [Abstract]
Other Long-term Assets	At September 30, 2024 and December 31, 2023, other long-term assets consisted of the following: September 30, December 31, Prepayments for property, plant and equipment $ 17,732 $ 3,380 Lease deposits 920 834 Security deposit for land use right 703 696 Others 1,997 1,140 Total other long-term assets $ 21,352 $ 6,050

SHORT-TERM BORROWINGS (Tables)

SHORT-TERM BORROWINGS (Tables)	9 Months Ended
	Sep. 30, 2024
Debt Disclosure [Abstract]
Short-Term Borrowings	At September 30, 2024 and December 31, 2023, s hort-term borrowings consisted of the following: September 30, December 31, Line of credit up to RMB 150,000 from China Everbright Bank, 1)due on August 29, 2024 with an annual interest rate of 3.00%. - 2,463 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 2)due on March 20, 2025 with an annual interest rate of 2.75%. 17,136 - 3)due on September 22, 2025 with an annual interest rate of 2.50%. 5,711 - 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 18)due on February 27, 2025 with an annual interest rate of 2.60%. 1,356 - 19)due on February 28, 2025 with an annual interest rate of 2.60%. 1,356 - 20)due on March 1, 2025 with an annual interest rate of 2.60%. 1,356 - 21)due on March 5, 2025 with an annual interest rate of 2.60%. 1,357 - 22)due on March 8, 2025 with an annual interest rate of 2.60%. 1,285 - 23)due on August 27, 2025 with an annual interest rate of 2.60%. 1,357 - 24)due on September 11, 2025 with an annual interest rate of 2.60%. 1,357 - 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%. 1,524 1,544 Total $ 33,795 $ 31,335

OTHER PAYABLES AND ACCRUED EX_2

OTHER PAYABLES AND ACCRUED EXPENSES (Tables)	9 Months Ended
	Sep. 30, 2024
Payables and Accruals [Abstract]
Other Payables and Accrued Expenses	At September 30, 2024 and December 31, 2023, other payables and accrued expenses consisted of the following: September 30, December 31, Accrued commissions $ 20,968 $ 15,572 Accrued warranty 11,877 9,834 Accrued payroll 18,632 14,840 Accrued professional fees 412 696 Accrued machine testing fees 1,710 1,762 Accrued machine sales fees 8,431 6,010 Accrued Lingang construction fees 28,413 33,729 Others 24,945 20,508 Total $ 115,388 $ 102,951
Schedule of Product Warranty Liability	Changes in the Company’s accrued warranty were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Balance at beginning of period $ 11,273 $ 9,179 $ 9,834 $ 8,780 Warranties accrued during the period 3,193 2,386 8,291 5,381 Settlements made during the period (2,589) (1,117) (6,248) (3,713) Balance at end of period $ 11,877 $ 10,448 $ 11,877 $ 10,448

LEASES (Tables)

LEASES (Tables)	9 Months Ended
	Sep. 30, 2024
Leases [Abstract]
Components of Lease Expense	The components of lease expense were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Operating lease cost $ 844 $ 899 $ 2,848 $ 2,639 Short-term lease cost 313 267 986 859 Total lease cost $ 1,157 $ 1,166 $ 3,834 $ 3,498
Supplemental Cash Flow Information Related to Operating Leases	Supplemental cash flow information related to operating leases was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Operating cash outflow from operating leases $ 844 $ 899 $ 2,848 $ 2,639 Operating lease right-of-use assets obtained (removed) in exchange for new (cancelled) operating lease liabilities $ (17) $ (714) $ 604 $ 5,878
Maturities of Outstanding Lease Liabilities for Operating Leases	As of September 30, 2024, maturities of outstanding lease liabilities for all operating leases were as follows: December 31, remainder of 2024 $ 916 2025 2,139 2026 1,355 2027 1,206 2028 and thereafter 638 Total lease payments $ 6,254 Less: Interest (574) Present value of lease liabilities $ 5,680
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: September 30, December 31, Remaining lease term and discount rate: Weighted average remaining lease term (years) 3.17 3.44 Weighted average discount rate 3.85 % 3.91 %

LONG-TERM BORROWINGS (Tables)

LONG-TERM BORROWINGS (Tables)	9 Months Ended
	Sep. 30, 2024
Long-Term Debt, by Current and Noncurrent [Abstract]
Long-Term Borrowings	At September 30, 2024 and December 31, 2023, long-term borrowings consisted of the following: September 30, December 31, Loan from China Merchants Bank $ 12,221 $ 13,362 Loans from Agricultural Bank of China 2,771 — Loans from Bank of China 29,129 5,013 Loan from Bank of Shanghai 14,280 14,120 Loans from China CITIC Bank 28,509 28,240 Loan from China Everbright Bank 49,829 — Less: Current portion (30,670) (6,783) Total $ 106,069 $ 53,952
Principal Payments for Outstanding Long-Term Loan	Scheduled principal payments for the outstanding long-term loan, including the current portion, as of September 30, 2024 are as follows: Year ending December 31 remainder of 2024 $ 674 2025 44,867 2026 26,073 2027 56,236 2028 2,025 Thereafter 6,864 $ 136,739

OTHER LONG-TERM LIABILITIES (Ta

OTHER LONG-TERM LIABILITIES (Tables)	9 Months Ended
	Sep. 30, 2024
Other Liabilities Disclosure [Abstract]
Other Long-Term Liabilities	At September 30, 2024 and December 31, 2023, other long-term liabilities consisted of the following unearned government subsidies: September 30, 2024 December 31, 2023 Subsidies commenced in 2020 and prior $ 789 $ 1,107 Subsidies to SW Lingang R&D development commenced in 2021 3,486 3,467 Other 1,410 1,299 Total $ 5,685 $ 5,873

LONG-TERM INVESTMENTS (Tables)

LONG-TERM INVESTMENTS (Tables)	9 Months Ended
	Sep. 30, 2024
Long-Term Investments [Abstract]
Long-Term Investment	Equity investee: Initial investment dates Investment entity Percent ownership by ACM and subsidiaries Investment purchase price Ninebell Co., Ltd. ("Ninebell") September 2017 ACM 20.0% $ 1,200 Wooil Flucon Co. ("Wooil") August 2022 ACM Singapore 20.0% $ 1,000 Hefei Shixi Chanheng Integrated Circuit Industry Venture Capital FundPartnership (LP) (“Hefei Shixi”) September 2019 ACM Shanghai 10.0% RMB 30,000 ($4,200) Shengyi Semiconductor Technology Co., Ltd. ("Shengyi") June 2019 ACM Shanghai 14.0% $ 109 Company D February 2024 ACM Shanghai 16.7% RMB 30,000 ($4,230) Investments accounted for using measurement alternative: Waferworks (Shanghai) Co., Ltd. (“Waferworks”) October 2021 ACM Shanghai 0.3% $ 1,568 Shengyi September 2023 ACM Shanghai 1.0% RMB 6,100 ($860) Company A September 2023 ACM Shanghai 4.4% RMB 30,000 ($4,200) Company B November 2023 ACM Shanghai 1.4% RMB 6,600 ($930) Company C February 2024 ACM Shanghai 5.0% RMB 12,500 ($1,760) Company E April 2024 ACM Shanghai 0.6% RMB 10,000 ($1,403) Equity investee: September 30, December 31, Ninebell $ 6,516 $ 5,632 Wooil 944 1,003 Shengyi 2,594 1,693 Hefei Shixi 7,047 9,174 Company D 4,281 — Subtotal 21,382 17,502 Investments accounted for using measurement alternative: Waferworks — 1,412 Shengyi 867 857 Company A 4,281 4,236 Company B 942 932 Company C 1,784 — Company E 1,427 — Other 2,972 2,941 Subtotal measurement alternative 12,273 10,378 Total 33,655 27,880

SHORT-TERM INVESTMENTS (Tables)

SHORT-TERM INVESTMENTS (Tables)	9 Months Ended
	Sep. 30, 2024
Investments, Debt and Equity Securities [Abstract]
Components of Trading Securities	At September 30, 2024 and December 31, 2023, the components of short-term investments were as follows: September 30, December 31, Short-term investments listed in Shanghai Stock Exchange Cost $ 21,045 $ 20,155 Market value 20,351 21,312
Unrealized Gain (Loss) on Trading Securities	For the three and nine months ended September 30, 2024 and 2023, the net gains (losses) recognized on equity securities were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Unrealized gains (losses) recognized during the reporting period on short-term investment still held at September 30 $ 413 $ (1,319) $ (1,151) $ (4,428) Net gains recognized during the period on short-term sold during the period $ 171 $ 656 $ 444 $ 8,569 Total net gains (losses) recognized at September 30 on short-term investment $ 584 $ (663) $ (707) $ 4,141

RELATED PARTY BALANCES AND TR_2

RELATED PARTY BALANCES AND TRANSACTIONS (Tables)	9 Months Ended
	Sep. 30, 2024
Related Party Transactions [Abstract]
Related Party Balances and Transactions	The following tables reflect related party transactions in our condensed consolidated financial statements: Advances to related party September 30, December 31, Ninebell $ 1,453 $ 2,432 Accounts payable September 30, December 31, Ninebell $ 10,042 $ 7,624 Shengyi 5,350 3,783 Total $ 15,392 $ 11,407 Three Months Ended September 30, Nine Months Ended September 30, Purchase of materials 2024 2023 2024 2023 Ninebell $ 13,791 $ 6,830 $ 41,721 $ 33,831 Shengyi 1,485 1,122 4,826 3,801 Total $ 15,276 $ 7,952 $ 46,547 $ 37,632 Three Months Ended September 30, Nine Months Ended September 30, Service fee charged by 2024 2023 2024 2023 Shengyi $ 125 $ 79 $ 352 $ 809

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	9 Months Ended
	Sep. 30, 2024
Share-Based Payment Arrangement [Abstract]
Summary of Share Option Activities	The following table summarizes the Company’s employee share option activities during the nine months ended September 30, 2024: Number of Weighted Weighted Weighted Average Outstanding at December 31, 2023 9,998,637 $ 5.15 $ 9.47 6.17 years Granted 460,500 15.31 20.69 Exercised (1,220,340) 2.25 4.81 Forfeited/cancelled (64,288) 12.04 25.43 Outstanding at September 30, 2024 9,174,509 $ 6.00 $ 10.54 5.90 years Vested and exercisable at September 30, 2024 5,656,683 The following table summarizes the Company’s non-employee share option activities during the nine months ended September 30, 2024: Number of Weighted Weighted Weighted Outstanding at December 31, 2023 1,170,795 $ 0.42 $ 1.31 2.66 years Exercised (268,007) 0.22 0.50 Forfeited/cancelled (5,878) 0.22 0.50 Outstanding at September 30, 2024 896,910 $ 0.48 $ 1.56 2.51 years Vested and exercisable at September 30, 2024 896,910 The following table summarizes the stock option activities of the ACM Shanghai 2019 Subsidiary Stock Option Plan during the nine months ended September 30, 2024: Number of Weighted Weighted Weighted Outstanding at December 31, 2023 3,134,883 $ 0.24 $ 1.85 0.85 years Exercised (446,154) $ 0.20 $ 1.85 Forfeited/cancelled (92,308) 0.22 $ 1.85 Outstanding at September 30, 2024 2,596,421 $ 0.20 $ 1.85 0.51 years Vested and exercisable at September 30, 2024 2,596,421 The following table summarizes the ACM Shanghai 2023 Subsidiary Stock Option Plan’s stock option activities during the three months ended September 30, 2024: Number of Option Shares in ACM Shanghai Weighted Weighted Weighted Outstanding at December 31, 2023 10,575,500 $ 9.49 $ 7.06 3.09 years Granted 1,391,000 $ 6.04 $ 7.00 Forfeited/cancelled (293,065) $ 9.09 $ 7.06 Outstanding at September 30, 2024 11,673,435 $ 9.01 $ 7.00 2.45 years Vested and exercisable at September 30, 2024 -
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 with following assumptions: Nine Months Ended Fair value of share of common stock(1) $23.02-$31.92 Expected term in years(2) 5.81-6.25 Volatility(3) 84.87%-85.48% Risk-free interest rate(4) 4.23%-4.49% Expected dividend(5) —% (1) Fair value of Class A common stock value was 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: Nine Months Ended September 30, 2024 Fair value of share of common stock (1) $4.93-$6.89 Expected term in years (2) 1.50-4.50 Volatility (3) 45.92%-56.18% Risk-free interest rate (4) 1.50%-2.75% Expected dividend (5) —% (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 Shanghai 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. (5) Expected dividend is assumed to be 0% as the impact is adjusted on the value of share of common stock.
Summary of Components of Stock-based Compensation Expense	The following table summarizes the components of stock-based compensation expense included in the condensed consolidated statements of comprehensive income: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Stock-Based Compensation Expense: Cost of revenue $ 447 $ 588 $ 2,020 $ 838 Sales and marketing expense 2,594 2,543 8,645 3,405 Research and development expense 3,373 3,421 12,082 4,831 General and administrative expense 5,467 4,029 18,045 5,592 $ 11,881 $ 10,581 $ 40,792 $ 14,666 Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Stock-based compensation expense by type: Employee stock purchase plan $ 2,860 $ 2,352 $ 7,602 $ 6,345 Non-employee stock purchase plan 21 12 30 35 2019 and 2023 Subsidiary option grants 9,000 8,217 33,160 8,286 $ 11,881 $ 10,581 $ 40,792 $ 14,666

INCOME TAXES (Tables)

INCOME TAXES (Tables)	9 Months Ended
	Sep. 30, 2024
Income Tax Disclosure [Abstract]
Income Tax Benefit (Expense)	Income tax expense was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Total income tax expense $ (4,007) $ (718) $ (17,712) $ (11,235)

SEGMENT INFORMATION (Tables)

SEGMENT INFORMATION (Tables)	9 Months Ended
	Sep. 30, 2024
Segment Reporting [Abstract]
Long-Lived Assets by Geography	Long-lived assets by geographic region as of the periods ended were as follows: September 30, December 31, Long-lived assets by geography: Mainland China $ 263,930 $ 209,725 Korea 12,497 12,190 United States 9,024 1,276 Total $ 285,451 $ 223,191

DESCRIPTION OF BUSINESS (Detail

DESCRIPTION OF BUSINESS (Details)	Sep. 30, 2024	Dec. 31, 2023
ACM Research (Shanghai), Inc. ("ACM Shanghai")
Description of Business [Abstract]
Effective interest held as at	82%	82.10%
ACM Research (Wuxi), Inc. ("ACM Wuxi")
Description of Business [Abstract]
Effective interest held as at	82%	82.10%
CleanChip Technologies Limited ("CleanChip")
Description of Business [Abstract]
Effective interest held as at	82%	82.10%
ACM Research Korea CO., LTD.
Description of Business [Abstract]
Effective interest held as at	82%	82.10%
ACM Research (Lingang), Inc. ("ACM Lingang")
Description of Business [Abstract]
Effective interest held as at	82%	82.10%
ACM Research (CA), Inc. ("ACM California")
Description of Business [Abstract]
Effective interest held as at	82%	82.10%
ACM Research (Cayman), Inc.
Description of Business [Abstract]
Effective interest held as at	100%	100%
ACM Research (Singapore) PTE. Ltd. ("ACM Singapore")
Description of Business [Abstract]
Effective interest held as at	100%	100%
ACM Research (Beijing), Inc. ("ACM Beijing")
Description of Business [Abstract]
Effective interest held as at	82%	82.10%
Hanguk ACM CO., LTD
Description of Business [Abstract]
Effective interest held as at	100%	100%
Yusheng Micro Semiconductor (Shanghai) Co., Ltd.
Description of Business [Abstract]
Effective interest held as at	82%	82.10%
ACM-Wooil Microelectronics (Shanghai) Co., Ltd.
Description of Business [Abstract]
Effective interest held as at	59.30%	59.40%

SUMMARY OF SIGNIFICANT ACCOUN_4

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash, cash equivalents and restricted cash and time deposits	$ 333,472		$ 333,472		$ 182,090
Short-term and long-term time deposits	33,821		33,821		121,342
ACM Shanghai
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash payments for procurement of goods and services	2,335	$ 10,724	16,734	$ 36,155
United States
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash, cash equivalents and restricted cash and time deposits	59,039		59,039		43,614
Mainland China
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash, cash equivalents and restricted cash and time deposits	80,115		80,115		70,418
China Hong Kong
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash, cash equivalents and restricted cash and time deposits	190,948		190,948		64,057
Korea
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash, cash equivalents and restricted cash and time deposits	3,303		3,303		3,934
Singapore
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash, cash equivalents and restricted cash and time deposits	$ 67		$ 67		$ 67

SUMMARY OF SIGNIFICANT ACCOUN_5

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Time Deposits (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Deposits Assets [Line Items]
Short-term and long-term time deposits	$ 33,821		$ 33,821		$ 121,342
Interest income, deposits with financial institutions	486	$ 867	2,779	$ 1,732
Deposit in China Merchant Bank which matured on January 29, 2024 with an annual interest rate of 2.85%
Deposits Assets [Line Items]
Time deposits, interest rate					2.85%
Short-term and long-term time deposits	0		0		$ 29,797
Deposit in Bank of Ningbo which matured on February 17, 2024 with an annual interest rate of 2.85%
Deposits Assets [Line Items]
Time deposits, interest rate					2.85%
Short-term and long-term time deposits	0		0		$ 44,630
Deposit in Shanghai Pudong Development Bank which was redeemed on June 20, 2024 with an annual interest rate of 3.10%
Deposits Assets [Line Items]
Time deposits, interest rate					3.10%
Short-term and long-term time deposits	0		0		$ 7,322
Deposit in Shanghai Pudong Development Bank which was redeemed on May 28, 2024 with an annual interest rate of 3.10%
Deposits Assets [Line Items]
Time deposits, interest rate					3.10%
Short-term and long-term time deposits	0		0		$ 7,307
Deposit in Shanghai Pudong Development Bank which was redeemed on March 7, 2024 with an annual interest rate of 3.10%
Deposits Assets [Line Items]
Time deposits, interest rate					3.10%
Short-term and long-term time deposits	0		0		$ 4,376
Deposit in Shanghai Pudong Development Bank which was redeemed on March 22, 2024 with an annual interest rate of 3.10%
Deposits Assets [Line Items]
Time deposits, interest rate					3.10%
Short-term and long-term time deposits	0		0		$ 4,373
Deposit in Shanghai Pudong Development Bank which was redeemed on January 29, 2024 with an annual interest rate of 3.10%
Deposits Assets [Line Items]
Time deposits, interest rate					3.10%
Short-term and long-term time deposits	0		$ 0		$ 2,912
Deposit in China Industrial Bank which matures on January 30, 2026 with an annual interest rate of 3.15%
Deposits Assets [Line Items]
Time deposits, interest rate			3.15%
Short-term and long-term time deposits	13,517		$ 13,517		$ 14,528
Deposit in China Everbright Bank which matured on January 5, 2024 with an annual interest rate of 5.38%
Deposits Assets [Line Items]
Time deposits, interest rate					5.38%
Short-term and long-term time deposits	0		0		$ 3,079
Deposit in China Everbright Bank which matured on May 22, 2024 with an annual interest rate of 5.38%
Deposits Assets [Line Items]
Time deposits, interest rate					5.38%
Short-term and long-term time deposits	0		$ 0		$ 3,018
Deposit in China Everbright Bank which matures on January 9, 2025 with an annual interest rate of 5.29%
Deposits Assets [Line Items]
Time deposits, interest rate			5.29%
Short-term and long-term time deposits	10,116		$ 10,116		0
Deposit in China Everbright Bank which matures on November 23, 2024 with an annual interest rate of 5.28%
Deposits Assets [Line Items]
Time deposits, interest rate			5.28%
Short-term and long-term time deposits	$ 10,188		$ 10,188		$ 0

SUMMARY OF SIGNIFICANT ACCOUN_6

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Summary of Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Fair Value, Recurring
Assets
Cash and cash equivalents	$ 32,943	$ 37,518
Short-term investments	20,351	21,312
Total assets	53,294	58,830
Fair Value, Nonrecurring
Assets
Investments accounted for using measurement alternative		10,378
Total assets		10,378
Quoted Prices in Active Markets for Identical Liabilities (Level 1) | Fair Value, Recurring
Assets
Cash and cash equivalents	32,943	37,518
Short-term investments	20,351	21,312
Total assets	53,294	58,830
Quoted Prices in Active Markets for Identical Liabilities (Level 1) | Fair Value, Nonrecurring
Assets
Investments accounted for using measurement alternative		0
Total assets		0
Significant Other Observable Inputs (Level 2) | Fair Value, Recurring
Assets
Cash and cash equivalents	0	0
Short-term investments	0	0
Total assets	0	0
Significant Other Observable Inputs (Level 2) | Fair Value, Nonrecurring
Assets
Investments accounted for using measurement alternative		0
Total assets		0
Significant Unobservable Inputs (Level 3) | Fair Value, Recurring
Assets
Cash and cash equivalents	0	0
Short-term investments	0	0
Total assets	$ 0	0
Significant Unobservable Inputs (Level 3) | Fair Value, Nonrecurring
Assets
Investments accounted for using measurement alternative		10,378
Total assets		$ 10,378

SUMMARY OF SIGNIFICANT ACCOUN_7

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Basic and Diluted Net Income per Common Share (Details) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($) class $ / shares shares	Sep. 30, 2023 USD ($) class $ / shares shares	Sep. 30, 2024 USD ($) class $ / shares shares	Sep. 30, 2023 USD ($) class $ / shares shares
Numerator [Abstract]
Net income	$ 38,672	$ 30,994	$ 92,163	$ 73,554
Less: Net income attributable to non-controlling interests	7,768	5,315	19,616	13,905
Net income available to common stockholders, basic	30,904	25,679	72,547	59,649
Less: Dilutive effect arising from stock-based awards by ACM Shanghai	585	461	1,503	1,338
Net income available to common stockholders, diluted	$ 30,319	$ 25,218	$ 71,044	$ 58,311
Weighted average shares outstanding, basic (in shares) | shares	62,500,903	60,219,218	62,017,257	59,953,144
Effect of dilutive securities (in shares) | shares	4,170,623	5,231,723	4,494,886	4,880,907
Weighted average shares outstanding, diluted (in shares) | shares	66,671,526	65,450,941	66,512,143	64,834,051
Net income per common share [Abstract]
Basic (in dollars per share) | $ / shares	$ 0.49	$ 0.43	$ 1.17	$ 0.99
Diluted (in dollars per share) | $ / shares	$ 0.45	$ 0.39	$ 1.07	$ 0.90
Classes of common stock outstanding | class	2	2	2	2
Incremental common shares attributable to dilutive effect of share-based payment arrangements (in shares) | shares	1,397,590	1,757,605	887,985	4,099,228

SUMMARY OF SIGNIFICANT ACCOUN_8

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Concentration of Credit Risk (Details) - Customer Concentration Risk	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Revenue Benchmark | Four Customers
Concentration of Credit Risk [Abstract]
Concentration risk, percentage	62.30%		56.30%
Revenue Benchmark | Two Customers
Concentration of Credit Risk [Abstract]
Concentration risk, percentage		53.20%
Revenue Benchmark | Three Customers
Concentration of Credit Risk [Abstract]
Concentration risk, percentage				48.80%
Accounts Receivable | Four Customers
Concentration of Credit Risk [Abstract]
Concentration risk, percentage					59.10%
Accounts Receivable | Three Customers
Concentration of Credit Risk [Abstract]
Concentration risk, percentage			51.60%

REVENUE FROM CONTRACTS WITH C_3

REVENUE FROM CONTRACTS WITH CUSTOMERS - Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Disaggregated Revenue Information [Abstract]
Revenues	$ 203,976	$ 168,569	$ 558,647	$ 387,402
Mainland China
Disaggregated Revenue Information [Abstract]
Revenues	203,672	168,302	552,642	375,528
Other regions
Disaggregated Revenue Information [Abstract]
Revenues	304	267	6,005	11,874
Single Wafer Cleaning, Tahoe and Semi-Critical Cleaning Equipment
Disaggregated Revenue Information [Abstract]
Revenues	160,985	132,417	423,676	281,559
ECP (front-end and packaging), Furnace and Other Technologies
Disaggregated Revenue Information [Abstract]
Revenues	34,600	25,508	99,362	71,223
Advanced Packaging (excluding ECP), Services & Spares
Disaggregated Revenue Information [Abstract]
Revenues	$ 8,391	$ 10,644	$ 35,609	$ 34,620

REVENUE FROM CONTRACTS WITH C_4

REVENUE FROM CONTRACTS WITH CUSTOMERS - Accounts Receivables and Contract Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Revenue from Contract with Customer [Abstract]
Accounts receivable	$ 370,589	$ 283,186
Advances from customers	215,678	181,368
Deferred revenue	$ 10,138	$ 3,687

REVENUE FROM CONTRACTS WITH C_5

REVENUE FROM CONTRACTS WITH CUSTOMERS - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Disaggregation of Revenue [Line Items]
Advances from customers			$ 32,778	$ 42,340
Revenue recognized from amounts included in contract liabilities at the beginning of the year	$ 28,077	$ 24,138	114,260	$ 70,023
First-Tools
Disaggregation of Revenue [Line Items]
Advances from customers			$ 34,300

ACCOUNTS RECEIVABLE (Details)

ACCOUNTS RECEIVABLE (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Accounts Receivable [Abstract]
Accounts receivable	$ 380,449	$ 288,016
Less: Allowance for credit losses	(9,860)	(4,830)
Total accounts receivable, net	370,589	$ 283,186
Accounts receivable [Abstract]
Increase accounts receivable	87,400
Increase in revenue	$ 171,200

ACCOUNTS RECEIVABLE - Summary o

ACCOUNTS RECEIVABLE - Summary of Allowance For Doubtful Accounts (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2024 USD ($)
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ (4,830)
Provision for credit losses, net	(5,030)
Ending balance	$ (9,860)

INVENTORIES (Details)

INVENTORIES (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Inventory, Net [Abstract]
Raw materials	$ 250,326		$ 250,326		$ 235,062
Work-in-process	79,469		79,469		81,438
Finished goods	298,925		298,925		228,895
Total inventory, net	628,720		628,720		545,395
Increase in raw materials and work in process			15,264
Increase in finished goods			$ 70,030
Inventory impairment, period			3 years
Inventory write-down	849	$ 1,807	$ 3,858	$ 5,031
First-tools, Customer Ownership
Inventory, Net [Abstract]
Finished goods	$ 196,987		$ 196,987		$ 123,390

PROPERTY, PLANT AND EQUIPMENT_3

PROPERTY, PLANT AND EQUIPMENT, NET (Details) ¥ in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 CNY (¥)	Dec. 31, 2023 USD ($)
Property, Plant and Equipment, Net, by Type [Abstract]
Property cost	$ 123,505		$ 123,505			$ 112,911
Less: Total accumulated depreciation and amortization	(23,631)		(23,631)			(17,503)
Construction in progress	150,225		150,225			106,440
Total property, plant and equipment, net	250,099		250,099			201,848
Depreciation and amortization expense	2,389	$ 2,023	7,073	$ 5,077
Buildings and plants
Property, Plant and Equipment, Net, by Type [Abstract]
Property cost	89,548		89,548			83,109
Buildings and plants | ACM Lingang
Property, Plant and Equipment, Net, by Type [Abstract]
Property cost	35,639		35,639		¥ 249,746
Buildings and plants | ACM Shanghai
Property, Plant and Equipment, Net, by Type [Abstract]
Property cost	53,909		53,909		¥ 377,779
Manufacturing equipment
Property, Plant and Equipment, Net, by Type [Abstract]
Property cost	19,248		19,248			16,556
Office equipment
Property, Plant and Equipment, Net, by Type [Abstract]
Property cost	5,896		5,896			4,953
Transportation equipment
Property, Plant and Equipment, Net, by Type [Abstract]
Property cost	409		409			404
Leasehold improvement
Property, Plant and Equipment, Net, by Type [Abstract]
Property cost	$ 8,404		$ 8,404			$ 7,889

LAND USE RIGHT, NET - Summary o

LAND USE RIGHT, NET - Summary of Land Use Right (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Land Use Right, Net [Abstract]
Land use right purchase amount	$ 9,092	$ 8,996
Less: accumulated amortization	(772)	(629)
Land use right, net	$ 8,320	$ 8,367

LAND USE RIGHT, NET - Narrative

LAND USE RIGHT, NET - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Land Use Right, Net [Abstract]
Amortization	$ 58	$ 44	$ 143	$ 136

LAND USE RIGHT, NET - Summary_2

LAND USE RIGHT, NET - Summary of Future Amortization (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Annual Amortization of Land use Right [Abstract]
remainder of 2024	$ 45
2025	182
2026	182
2027	182
2028	182
2029 and thereafter	7,547
Land use right, net	$ 8,320	$ 8,367

OTHER LONG-TERM ASSETS - Summar

OTHER LONG-TERM ASSETS - Summary of Other Long-term Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Other Assets, Noncurrent Disclosure [Abstract]
Prepayments for property, plant and equipment	$ 17,732	$ 3,380
Lease deposits	920	834
Security deposit for land use right	703	696
Others	1,997	1,140
Total other long-term assets	$ 21,352	$ 6,050

SHORT-TERM BORROWINGS (Details)

SHORT-TERM BORROWINGS (Details) ₩ in Thousands, ¥ in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 CNY (¥)	Sep. 30, 2024 KRW (₩)	Dec. 31, 2023 USD ($)	Dec. 31, 2023 CNY (¥)	Dec. 31, 2023 KRW (₩)
Short-Term Borrowings [Abstract]
Short-term debt	$ 33,795		$ 33,795				$ 31,335
Interest expense related to short-term borrowings	373	$ 364	$ 1,011	$ 1,338
Line of Credit up to RMB 150,000 from China Everbright Bank
Short-Term Borrowings [Abstract]
Line of credit facility, maximum borrowing capacity | ¥					¥ 150,000			¥ 150,000
Line of Credit, due on August 29, 2024 with an annual interest rate of 3.00%
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			3%
Short-term debt	0		$ 0				2,463
Line of Credit up to RMB 40,000 from Bank of China,
Short-Term Borrowings [Abstract]
Line of credit facility, maximum borrowing capacity | ¥					40,000			40,000
Line of Credit, due on September 7, 2024 with an annual interest rate of 2.87%
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			2.87%
Short-term debt	0		$ 0				5,648
Line of Credit, due on March 20, 2025 with an annual interest rate of 2.75%.
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			2.75%
Short-term debt	17,136		$ 17,136				0
Line of Credit, due on September 22, 2025 with an annual interest rate of 2.5%.
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			2.50%
Short-term debt	5,711		$ 5,711				0
Line of Credit up to RMB 200,000 from China Merchants Bank
Short-Term Borrowings [Abstract]
Line of credit facility, 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 Borrowings [Abstract]
Line of credit facility, interest rate during period			3%
Short-term debt	0		$ 0				1,271
Line of Credit, China Merchants Bank, due on August 8, 2024 with an annual interest rate of 3.00%
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			3%
Short-term debt	0		$ 0				1,271
Line of Credit, China Merchants Bank, due on August 9, 2024 with an annual interest rate of 3.00%
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			3%
Short-term debt	0		$ 0				1,271
Line of Credit, China Merchants Bank, due on August 14, 2024 with an annual interest rate of 3.00%
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			3%
Short-term debt	0		$ 0				1,271
Line of Credit, China Merchants Bank, due on August 17, 2024 with an annual interest rate of 3.00%
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			3%
Short-term debt	0		$ 0				1,271
Line of Credit, China Merchants Bank, due on August 20, 2024 with an annual interest rate of 3.00%
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			3%
Short-term debt	0		$ 0				1,271
Line of Credit, China Merchants Bank, due on August 21, 2024 with an annual interest rate of 3.00%
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			3%
Short-term debt	0		$ 0				1,271
Line of Credit, China Merchants Bank, due on August 22, 2024 with an annual interest rate of 3.00%
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			3%
Short-term debt	0		$ 0				1,271
Line of Credit, China Merchants Bank, due on August 24, 2024 with an annual interest rate of 3.00%
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			3%
Short-term debt	0		$ 0				1,271
Line of Credit, China Merchants Bank, due on August 27, 2024 with an annual interest rate of 3.00%
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			3%
Short-term debt	0		$ 0				1,271
Line of Credit, China Merchants Bank, due on August 29, 2024 with an annual interest rate of 3.00%
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			3%
Short-term debt	0		$ 0				1,271
Line of Credit, China Merchants Bank, due on August 30, 2024 with an annual interest rate of 3.00%
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			3%
Short-term debt	0		$ 0				1,271
Line of Credit, China Merchants Bank, due on September 3, 2024 with an annual interest rate of 3.00%
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			3%
Short-term debt	0		$ 0				1,271
Line of Credit, China Merchants Bank, due on September 5, 2024 with an annual interest rate of 3.00%
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			3%
Short-term debt	0		$ 0				1,270
Line of Credit, China Merchants Bank, due on September 6, 2024 with an annual interest rate of 3.00%
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			3%
Short-term debt	0		$ 0				1,270
Line of Credit, China Merchants Bank, due on September 10, 2024 with an annual interest rate of 3.00%
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			3%
Short-term debt	0		$ 0				1,270
Line of Credit, China Merchants Bank, due on September 12, 2024 with an annual interest rate of 3.00%
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			3%
Short-term debt	0		$ 0				1,270
Line Of Credit, China Merchants Bank, Due On February 27, 2025 With An Annual Interest Rate Of 2.60%
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			2.60%
Short-term debt	1,356		$ 1,356				0
Line Of Credit, China Merchants Bank, Due On February 28, 2025 With An Annual Interest Rate Of 2.60%
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			2.60%
Short-term debt	1,356		$ 1,356				0
Line Of Credit, China Merchants Bank, Due On March 1, 2025 With An Annual Interest Rate Of 2.60%
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			2.60%
Short-term debt	1,356		$ 1,356				0
Line Of Credit, China Merchants Bank, Due On March 5, 2025 With An Annual Interest Rate Of 2.60%
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			2.60%
Short-term debt	1,357		$ 1,357				0
Line Of Credit, China Merchants Bank, Due On March 8, 2025 With An Annual Interest Rate Of 2.60%
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			2.60%
Short-term debt	1,285		$ 1,285				0
Line Of Credit, China Merchants Bank, Due On August 27, 2025 With An Annual Interest Rate Of 2.60%
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			2.60%
Short-term debt	1,357		$ 1,357				0
Line Of Credit, China Merchants Bank, Due On September 11, 2025 With An Annual Interest Rate Of 2.60%
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			2.60%
Short-term debt	1,357		$ 1,357				0
Line Of Credit Up To KRW 500,000 from Industrial Bank Of Korea
Short-Term Borrowings [Abstract]
Line of credit facility, maximum borrowing capacity | ₩						₩ 500,000			₩ 500,000
Line Of Credit Due On July 12, 2024 With An Annual Interest Rate Of 6.03%
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			6.03%
Short-term debt	0		$ 0				77
Line Of Credit Up To KRW 2,000,000 From Industrial Bank Of Korea
Short-Term Borrowings [Abstract]
Line of credit facility, maximum borrowing capacity | ₩						₩ 2,000,000			₩ 2,000,000
Line Of Credit Due On December 15, 2024 With An Annual Interest Rate Of 4.29%
Short-Term Borrowings [Abstract]
Line of credit facility, interest rate during period			4.27%
Short-term debt	$ 1,524		$ 1,524				$ 1,544

OTHER PAYABLES AND ACCRUED EX_3

OTHER PAYABLES AND ACCRUED EXPENSES - Other Payables and Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Payables and Accruals [Abstract]
Accrued commissions	$ 20,968	$ 15,572
Accrued warranty	11,877	9,834
Accrued payroll	18,632	14,840
Accrued professional fees	412	696
Accrued machine testing fees	1,710	1,762
Accrued machine sales fees	8,431	6,010
Accrued Lingang construction fees	28,413	33,729
Others	24,945	20,508
Total	$ 115,388	$ 102,951

OTHER PAYABLES AND ACCRUED EX_4

OTHER PAYABLES AND ACCRUED EXPENSES - Schedule of Product Warranty Liability (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance at beginning of period	$ 11,273	$ 9,179	$ 9,834	$ 8,780
Warranties accrued during the period	3,193	2,386	8,291	5,381
Settlements made during the period	(2,589)	(1,117)	(6,248)	(3,713)
Balance at end of period	$ 11,877	$ 10,448	$ 11,877	$ 10,448

LEASES - Narrative (Details)

LEASES - Narrative (Details)	9 Months Ended
	Sep. 30, 2024 renewalOption
Leases [Abstract]
Number of renewal options	1

LEASES - Components of Lease Ex

LEASES - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Components of lease expense [Abstract]
Operating lease cost	$ 844	$ 899	$ 2,848	$ 2,639
Short-term lease cost	313	267	986	859
Total lease cost	$ 1,157	$ 1,166	$ 3,834	$ 3,498

LEASES - Supplemental Cash Flow

LEASES - Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Cash paid for amounts included in the measurement of lease liabilities [Abstract]
Operating cash outflow from operating leases	$ 844	$ 899	$ 2,848	$ 2,639
Right Of Use Asset Obtained In Exchange For Operating Lease Liability (Reversal)	$ (17)	$ (714)
Operating lease right-of-use assets obtained (removed) in exchange for new (cancelled) operating lease liabilities			$ (604)	$ (5,878)

LEASES - Maturities of Lease Li

LEASES - Maturities of Lease Liabilities (Details) $ in Thousands	Sep. 30, 2024 USD ($)
Maturities of outstanding lease liabilities [Abstract]
remainder of 2024	$ 916
2025	2,139
2026	1,355
2027	1,206
2028 and thereafter	638
Total lease payments	6,254
Less: Interest	(574)
Present value of lease liabilities	$ 5,680

LEASES - Weighted Average Remai

LEASES - Weighted Average Remaining Lease Term (Details)	Sep. 30, 2024	Dec. 31, 2023
Lessee, Operating Lease, Description [Abstract]
Weighted average remaining lease term (years)	3 years 2 months 1 day	3 years 5 months 8 days
Weighted average discount rate	3.85%	3.91%

LONG-TERM BORROWINGS - Summary

LONG-TERM BORROWINGS - Summary of Long-term Borrowings (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Long-Term Borrowings [Abstract]
Long-term debt	$ 136,739	$ 60,735
Less: Current portion	(30,670)	(6,783)
Total	106,069	53,952
China Merchants Bank
Long-Term Borrowings [Abstract]
Long-term debt	12,221	13,362
Agricultural Bank of China
Long-Term Borrowings [Abstract]
Long-term debt	2,771	0
Bank of China
Long-Term Borrowings [Abstract]
Long-term debt	29,129	5,013
Bank of Shanghai
Long-Term Borrowings [Abstract]
Long-term debt	14,280	14,120
Citic Bank
Long-Term Borrowings [Abstract]
Long-term debt	28,509	28,240
Everbright Bank
Long-Term Borrowings [Abstract]
Long-term debt	$ 49,829	$ 0

LONG-TERM BORROWINGS - Narrativ

LONG-TERM BORROWINGS - Narrative (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($) loan	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) installment loan	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Line of Credit Facility [Line Items]
Long-term debt	$ 136,739		$ 136,739		$ 60,735
Long-term debt, fair value	129,024		129,024		56,462
Interest costs incurred	835	$ 276	$ 1,912	$ 646
China Merchants Bank
Line of Credit Facility [Line Items]
Number of installments for loan repayable | installment			120
Line of credit facility, interest rate during period			3.95%
Long-term debt	$ 12,221		$ 12,221		13,362
Bank of China
Line of Credit Facility [Line Items]
Number of loans | loan	2		2
Long-term debt	$ 29,129		$ 29,129		5,013
Bank of China | Loan One
Line of Credit Facility [Line Items]
Number of installments for loan repayable | installment			6
Line of credit facility, interest rate during period			2.60%
Bank of China | Loan Two
Line of Credit Facility [Line Items]
Number of installments for loan repayable | installment			6
Line of credit facility, interest rate during period			2.62%
Bank of Shanghai
Line of Credit Facility [Line Items]
Line of credit facility, interest rate during period			2.85%
Long-term debt	14,280		$ 14,280		14,120
Citic Bank
Line of Credit Facility [Line Items]
Long-term debt	28,509		$ 28,509		28,240
Citic Bank | Loan One
Line of Credit Facility [Line Items]
Number of installments for loan repayable | installment			4
Line of credit facility, interest rate during period			3.10%
Citic Bank | Loan Two
Line of Credit Facility [Line Items]
Number of installments for loan repayable | installment			4
Line of credit facility, interest rate during period			4.50%
Everbright Bank
Line of Credit Facility [Line Items]
Number of installments for loan repayable | installment			6
Line of credit facility, interest rate during period			2.60%
Long-term debt	49,829		$ 49,829		0
Agricultural Bank of China
Line of Credit Facility [Line Items]
Long-term debt	$ 2,771		$ 2,771		$ 0
Agricultural Bank of China | Loan One
Line of Credit Facility [Line Items]
Number of installments for loan repayable | installment			120
Line of credit facility, interest rate during period			2.78%
Agricultural Bank of China | Loan Two
Line of Credit Facility [Line Items]
Number of installments for loan repayable | installment			120
Line of credit facility, interest rate during period			2.78%

LONG-TERM BORROWINGS - Summar_2

LONG-TERM BORROWINGS - Summary of Scheduled Principal Payments (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Principal Payments of Long-Term Loan [Abstract]
remainder of 2024	$ 674
2025	44,867
2026	26,073
2027	56,236
2028	2,025
Thereafter	6,864
Long-term debt	$ 136,739	$ 60,735

OTHER LONG-TERM LIABILITIES (De

OTHER LONG-TERM LIABILITIES (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Other Long-term Liabilities [Abstract]
Other long-term liabilities	$ 5,685	$ 5,873
Subsidies commenced in 2020 and prior
Other Long-term Liabilities [Abstract]
Other long-term liabilities	789	1,107
Subsidies to SW Lingang R&D development commenced in 2021
Other Long-term Liabilities [Abstract]
Other long-term liabilities	3,486	3,467
Other
Other Long-term Liabilities [Abstract]
Other long-term liabilities	$ 1,410	$ 1,299

LONG-TERM INVESTMENTS - Narrati

LONG-TERM INVESTMENTS - Narrative (Details) ¥ in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 CNY (¥)	Jan. 22, 2024 USD ($)	Jan. 22, 2024 CNY (¥)	Jan. 19, 2024 USD ($)	Jan. 19, 2024 CNY (¥)	Jan. 12, 2024 USD ($)	Jan. 12, 2024 CNY (¥)
Investments [Abstract]
Income (loss) from equity method investments (note 15)	$ 1,316	$ (160)	$ 101	$ 3,728
Dividends from equity investee	131	$ 52	731	$ 5,147
Company C | Common Stock Class A
Investments [Abstract]
Investment purchase price	$ 1,760		$ 1,760		¥ 12,500					$ 1,760	¥ 12,500
Percent ownership by ACM and subsidiaries	5%		5%		5%					5%	5%
Company D | Common Stock Class A
Investments [Abstract]
Investment purchase price	$ 4,230		$ 4,230		¥ 30,000			$ 4,230	¥ 30,000
Percent ownership by ACM and subsidiaries	16.70%		16.70%		16.70%			16.70%	16.70%
Company E | Common Stock Class A
Investments [Abstract]
Investment purchase price	$ 1,403		$ 1,403		¥ 10,000	$ 1,403	¥ 10,000
Percent ownership by ACM and subsidiaries	0.60%		0.60%		0.60%	0.60%	0.60%

LONG-TERM INVESTMENTS - Summary

LONG-TERM INVESTMENTS - Summary of Long Term Investments (Details) ¥ in Thousands, $ in Thousands	Sep. 30, 2024 USD ($)	Sep. 30, 2024 CNY (¥)	Jan. 22, 2024 USD ($)	Jan. 22, 2024 CNY (¥)	Jan. 19, 2024 USD ($)	Jan. 19, 2024 CNY (¥)	Jan. 12, 2024 USD ($)	Jan. 12, 2024 CNY (¥)	Dec. 31, 2023 USD ($)
Long-Term Investments [Line Items]
Total	$ 33,655								$ 27,880
Equity investee:
Long-Term Investments [Line Items]
Total	21,382								17,502
Investments accounted for using measurement alternative:
Long-Term Investments [Line Items]
Total	33,655								27,880
Ninebell | Equity investee:
Long-Term Investments [Line Items]
Total	$ 6,516								5,632
Ninebell | Common Stock Class A
Long-Term Investments [Line Items]
Percent ownership by ACM and subsidiaries	20%	20%
Investment purchase price	$ 1,200
Wooil | Equity investee:
Long-Term Investments [Line Items]
Total	$ 944								1,003
Wooil | Common Stock Class A
Long-Term Investments [Line Items]
Percent ownership by ACM and subsidiaries	20%	20%
Investment purchase price	$ 1,000
Hefei Shixi | Equity investee:
Long-Term Investments [Line Items]
Total	$ 7,047								9,174
Hefei Shixi | Common Stock Class A
Long-Term Investments [Line Items]
Percent ownership by ACM and subsidiaries	10%	10%
Investment purchase price	$ 4,200	¥ 30,000
Shengyi | Equity investee:
Long-Term Investments [Line Items]
Total	2,594								1,693
Shengyi | Investments accounted for using measurement alternative:
Long-Term Investments [Line Items]
Total	$ 867								857
Shengyi | Common Stock Class A
Long-Term Investments [Line Items]
Percent ownership by ACM and subsidiaries	14%	14%
Investment purchase price	$ 109
Company D | Equity investee:
Long-Term Investments [Line Items]
Total	$ 4,281								0
Company D | Common Stock Class A
Long-Term Investments [Line Items]
Percent ownership by ACM and subsidiaries	16.70%	16.70%			16.70%	16.70%
Investment purchase price	$ 4,230	¥ 30,000			$ 4,230	¥ 30,000
Waferworks | Investments accounted for using measurement alternative:
Long-Term Investments [Line Items]
Total	$ 0								1,412
Waferworks | Common Stock Class A
Long-Term Investments [Line Items]
Percent ownership by ACM and subsidiaries	0.30%	0.30%
Investment purchase price	$ 1,568
Shengyi | Common Stock Class A
Long-Term Investments [Line Items]
Percent ownership by ACM and subsidiaries	1%	1%
Investment purchase price	$ 860	¥ 6,100
Company A | Investments accounted for using measurement alternative:
Long-Term Investments [Line Items]
Total	$ 4,281								4,236
Company A | Common Stock Class A
Long-Term Investments [Line Items]
Percent ownership by ACM and subsidiaries	4.40%	4.40%
Investment purchase price	$ 4,200	¥ 30,000
Company B | Investments accounted for using measurement alternative:
Long-Term Investments [Line Items]
Total	$ 942								932
Company B | Common Stock Class A
Long-Term Investments [Line Items]
Percent ownership by ACM and subsidiaries	1.40%	1.40%
Investment purchase price	$ 930	¥ 6,600
Company C | Investments accounted for using measurement alternative:
Long-Term Investments [Line Items]
Total	$ 1,784								0
Company C | Common Stock Class A
Long-Term Investments [Line Items]
Percent ownership by ACM and subsidiaries	5%	5%					5%	5%
Investment purchase price	$ 1,760	¥ 12,500					$ 1,760	¥ 12,500
Company E | Investments accounted for using measurement alternative:
Long-Term Investments [Line Items]
Total	$ 1,427								0
Company E | Common Stock Class A
Long-Term Investments [Line Items]
Percent ownership by ACM and subsidiaries	0.60%	0.60%	0.60%	0.60%
Investment purchase price	$ 1,403	¥ 10,000	$ 1,403	¥ 10,000
Other | Investments accounted for using measurement alternative:
Long-Term Investments [Line Items]
Total	2,972								2,941
Subtotal measurement alternative | Investments accounted for using measurement alternative:
Long-Term Investments [Line Items]
Total	$ 12,273								$ 10,378

SHORT-TERM INVESTMENTS - Narrat

SHORT-TERM INVESTMENTS - Narrative (Details) ¥ in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 CNY (¥)	Feb. 29, 2024 USD ($)	Feb. 29, 2024 CNY (¥)	Sep. 30, 2023 CNY (¥)	Jul. 31, 2023 USD ($)	Jul. 31, 2023 CNY (¥)	Sep. 27, 2022 USD ($)	Sep. 27, 2022 CNY (¥)	Sep. 19, 2022 USD ($)	Sep. 19, 2022 CNY (¥)	Dec. 31, 2021 USD ($)	Dec. 31, 2021 CNY (¥)
Investments [Abstract]
Proceeds from the sale of short-term investments, including a realized gain	$ 171	$ 656	$ 444	$ 8,569
Nuode Asset Management Company Limited
Investments [Abstract]
Investment in partnership											$ 4,196	¥ 30,000	$ 22,160	¥ 160,000
Ownership percentage in partnership											18.75%	18.75%
Sale of short-term investments receivable	3,167		3,167		¥ 22,478
Huahong Semiconductor Limited
Investments [Abstract]
Investment in partnership									$ 13,930	¥ 100,000
Zhongiuxin Limited Company
Investments [Abstract]
Investment in partnership		4,179		4,179				¥ 30,000
Shanghai Syncrystalline Silicon Materials Co., Ltd
Investments [Abstract]
Investment in partnership	2,818		2,818		¥ 20,000	$ 1,409	¥ 10,000								$ 1,409	¥ 10,000
SMIC
Investments [Abstract]
Proceeds from sale of short-term investments	3,167	2,205	3,167	19,914
Proceeds from the sale of short-term investments, including a realized gain	$ 171	$ 656	$ 444	$ 8,569

SHORT-TERM INVESTMENTS - Summar

SHORT-TERM INVESTMENTS - Summary of Trading Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Cost	$ 21,045	$ 20,155
Market value	$ 20,351	$ 21,312

SHORT-TERM INVESTMENTS - Summ_2

SHORT-TERM INVESTMENTS - Summary of Unrealized Gain (Loss) on Trading Securities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Unrealized gains (losses) recognized during the reporting period on short-term investment still held at September 30	$ 413	$ (1,319)	$ (1,151)	$ (4,428)
Net gains recognized during the period on short-term sold during the period	171	656	444	8,569
Total net gains (losses) recognized at September 30 on short-term investment	$ 584	$ (663)	$ (707)	$ 4,141

RELATED PARTY BALANCES AND TR_3

RELATED PARTY BALANCES AND TRANSACTIONS (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Related Party Transaction [Line Items]
Purchase of materials	$ 15,276	$ 7,952	$ 46,547	$ 37,632
Cost of revenue, related party	99,142	80,055	277,908	190,263
Ninebell
Related Party Transaction [Line Items]
Purchase of materials	13,791	6,830	41,721	33,831
Shengyi
Related Party Transaction [Line Items]
Purchase of materials	1,485	1,122	4,826	3,801
Related Party
Related Party Transaction [Line Items]
Advances to related party	1,453		1,453		$ 2,432
Accounts payable	15,392		15,392		11,407
Cost of revenue, related party	15,276	7,952	46,547	37,632
Related Party | Ninebell
Related Party Transaction [Line Items]
Advances to related party	1,453		1,453		2,432
Accounts payable	10,042		10,042		7,624
Related Party | Shengyi
Related Party Transaction [Line Items]
Accounts payable	5,350		5,350		$ 3,783
Cost of revenue, related party	$ 125	$ 79	$ 352	$ 809

COMMON STOCK (Details)

COMMON STOCK (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2024 vote $ / shares shares	Sep. 30, 2023 shares	Sep. 30, 2024 vote $ / shares shares	Sep. 30, 2023 shares	Jun. 30, 2024 shares	Dec. 31, 2023 shares	Jun. 30, 2023 shares	Dec. 31, 2022 shares
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 | vote	1		1
Exercise of stock options (in shares)		623,244	1,488,347
Common stock issued (in shares)	57,524,519		57,524,519			56,036,172
Common stock outstanding (in shares)	57,524,519		57,524,519			56,036,172
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 | vote	20		20
Shares converted			1
Common stock issued (in shares)	5,021,811		5,021,811			5,021,811
Common stock outstanding (in shares)	5,021,811		5,021,811			5,021,811
Common Stock | Common Stock Class A
Class of Stock Disclosures [Abstract]
Exercise of stock options (in shares)	122,266	623,244	1,488,347	919,448
Common stock outstanding (in shares)	57,524,519	55,574,734	57,524,519	55,574,734	57,402,253	56,036,172	54,951,490	54,655,286
Common Stock | Class B Common Stock
Class of Stock Disclosures [Abstract]
Common stock outstanding (in shares)	5,021,811	5,021,811	5,021,811	5,021,811	5,021,811	5,021,811	5,021,811	5,021,811

STOCK-BASED COMPENSATION, Share

STOCK-BASED COMPENSATION, Share Option Activities (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2024	Dec. 31, 2023
Employee Share Option
Number of Option Share [Roll Forward]
Outstanding, beginning of period (in shares)		9,998,637
Granted (in shares)		460,500
Exercised (in shares)		(1,220,340)
Forfeited/cancelled (in shares)		(64,288)
Outstanding, end of period (in shares)	9,174,509	9,174,509	9,998,637
Vested and exercisable (in shares)	5,656,683	5,656,683
Weighted Average Grant Date Fair Value
Outstanding at beginning of period (in dollars per share)		$ 5.15
Granted (in dollars per share)		15.31
Exercised (in dollars per share)		2.25
Forfeited/cancelled (in dollars per share)		12.04
Outstanding at end of period (in dollars per share)	$ 6	6	$ 5.15
Weighted Average Exercise Price
Outstanding, beginning of period (in dollars per share)		9.47
Granted (in dollars per share)		20.69
Exercised (in dollars per share)		4.81
Forfeited/cancelled (in dollars per share)		25.43
Outstanding, end of period (in dollars per share)	$ 10.54	$ 10.54	$ 9.47
Weighted Average Remaining Contractual Term
Weighted average remaining contractual term		5 years 10 months 24 days	6 years 2 months 1 day
Unrecognized employee stock-based compensation expense	$ 25,929	$ 25,929
Cost not yet recognized (in years)		3 years 6 months
Intrinsic value	234	$ 29,311
Intrinsic value, outstanding	96,975	96,975
Intrinsic value, exercisable	$ 72,321	$ 72,321
Employee Share Option | ACM Shanghai | 2019 Stock Option Incentive Plan
Number of Option Share [Roll Forward]
Outstanding, beginning of period (in shares)		3,134,883
Exercised (in shares)		(446,154)
Forfeited/cancelled (in shares)		(92,308)
Outstanding, end of period (in shares)	2,596,421	2,596,421	3,134,883
Vested and exercisable (in shares)	2,596,421	2,596,421
Weighted Average Grant Date Fair Value
Outstanding at beginning of period (in dollars per share)		$ 0.24
Exercised (in dollars per share)		0.20
Forfeited/cancelled (in dollars per share)		0.22
Outstanding at end of period (in dollars per share)	$ 0.20	0.20	$ 0.24
Weighted Average Exercise Price
Outstanding, beginning of period (in dollars per share)		1.85
Exercised (in dollars per share)		1.85
Forfeited/cancelled (in dollars per share)		1.85
Outstanding, end of period (in dollars per share)	$ 1.85	$ 1.85	$ 1.85
Weighted Average Remaining Contractual Term
Weighted average remaining contractual term		6 months 3 days	10 months 6 days
Intrinsic value	$ 0	$ 5,198
Intrinsic value, outstanding	33,788	33,788
Intrinsic value, exercisable	$ 33,788	$ 33,788
Employee Share Option | ACM Shanghai | 2023 Subsidiary Stock Option Plan
Number of Option Share [Roll Forward]
Outstanding, beginning of period (in shares)		10,575,500
Granted (in shares)		1,391,000
Forfeited/cancelled (in shares)		(293,065)
Outstanding, end of period (in shares)	11,673,435	11,673,435	10,575,500
Vested and exercisable (in shares)	0	0
Weighted Average Grant Date Fair Value
Outstanding at beginning of period (in dollars per share)		$ 9.49
Granted (in dollars per share)		6.04
Forfeited/cancelled (in dollars per share)		9.09
Outstanding at end of period (in dollars per share)	$ 9.01	9.01	$ 9.49
Weighted Average Exercise Price
Outstanding, beginning of period (in dollars per share)		7.06
Granted (in dollars per share)		7
Forfeited/cancelled (in dollars per share)		7.06
Outstanding, end of period (in dollars per share)	$ 7	$ 7	$ 7.06
Weighted Average Remaining Contractual Term
Weighted average remaining contractual term		2 years 5 months 12 days	3 years 1 month 2 days
Unrecognized employee stock-based compensation expense	$ 50,887	$ 50,887
Cost not yet recognized (in years)		1 year 6 months
Employee Share Option | ACM Shanghai | 2023 Stock Option Incentive Plan
Weighted Average Remaining Contractual Term
Intrinsic value	0	$ 0
Intrinsic value, outstanding	91,501	91,501
Intrinsic value, exercisable	$ 0	$ 0
Non-Employee Stock Option
Number of Option Share [Roll Forward]
Outstanding, beginning of period (in shares)		1,170,795
Exercised (in shares)		(268,007)
Forfeited/cancelled (in shares)		(5,878)
Outstanding, end of period (in shares)	896,910	896,910	1,170,795
Vested and exercisable (in shares)	896,910	896,910
Weighted Average Grant Date Fair Value
Outstanding at beginning of period (in dollars per share)		$ 0.42
Exercised (in dollars per share)		0.22
Forfeited/cancelled (in dollars per share)		0.22
Outstanding at end of period (in dollars per share)	$ 0.48	0.48	$ 0.42
Weighted Average Exercise Price
Outstanding, beginning of period (in dollars per share)		1.31
Exercised (in dollars per share)		0.50
Forfeited/cancelled (in dollars per share)		0.50
Outstanding, end of period (in dollars per share)	$ 1.56	$ 1.56	$ 1.31
Weighted Average Remaining Contractual Term
Weighted average remaining contractual term		2 years 6 months 3 days	2 years 7 months 28 days
Intrinsic value	$ 2,247	$ 6,514
Intrinsic value, outstanding	16,809	16,809
Intrinsic value, exercisable	$ 16,809	$ 16,809

STOCK-BASED COMPENSATION, Assum

STOCK-BASED COMPENSATION, Assumptions Used to Determine Fair Value of Share Options Granted (Details) - Employee Share Option $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2024 USD ($) $ / shares
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Unrecognized employee stock-based compensation expense | $	$ 25,929
Cost not yet recognized (in years)	3 years 6 months
Service Period Based
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Volatility minimum	84.87%
Volatility maximum	85.48%
Risk free interest rate minimum	4.23%
Risk free interest rate maximum	4.49%
Expected dividend rate	0%
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)	$ 23.02
Expected term	5 years 9 months 21 days
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)	$ 31.92
Expected term	6 years 3 months
2023 Subsidiary Stock Option Plan | ACM Shanghai
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Volatility minimum	45.92%
Volatility maximum	56.18%
Risk free interest rate minimum	1.50%
Risk free interest rate maximum	2.75%
Expected dividend rate	0%
Unrecognized employee stock-based compensation expense | $	$ 50,887
Cost not yet recognized (in years)	1 year 6 months
2023 Subsidiary Stock Option Plan | Minimum | ACM Shanghai
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Fair value of common share (in dollars per share)	$ 4.93
Expected term	1 year 6 months
2023 Subsidiary Stock Option Plan | Maximum | ACM Shanghai
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Fair value of common share (in dollars per share)	$ 6.89
Expected term	4 years 6 months

STOCK-BASED COMPENSATION - Stoc

STOCK-BASED COMPENSATION - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Stock-based Compensation Expense [Abstract]
Stock-based compensation expense	$ 11,881	$ 10,581	$ 40,792	$ 14,666
Employee Stock Option Plan
Stock-based Compensation Expense [Abstract]
Stock-based compensation expense	2,860	2,352	7,602	6,345
Employee Stock Option Plan | ACM Shanghai
Stock-based Compensation Expense [Abstract]
Stock-based compensation expense	9,000	8,217	33,160	8,286
Non-Employee Stock Option Plan
Stock-based Compensation Expense [Abstract]
Stock-based compensation expense	21	12	30	35
Cost of revenue
Stock-based Compensation Expense [Abstract]
Stock-based compensation expense	447	588	2,020	838
Sales and marketing expense
Stock-based Compensation Expense [Abstract]
Stock-based compensation expense	2,594	2,543	8,645	3,405
Research and development expense
Stock-based Compensation Expense [Abstract]
Stock-based compensation expense	3,373	3,421	12,082	4,831
General and administrative expense
Stock-based Compensation Expense [Abstract]
Stock-based compensation expense	$ 5,467	$ 4,029	$ 18,045	$ 5,592

INCOME TAXES - Narrative (Detai

INCOME TAXES - Narrative (Details) $ in Thousands	3 Months Ended		9 Months Ended		36 Months Ended
	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) subsidiary	Sep. 30, 2023 USD ($)	Dec. 31, 2022	Dec. 31, 2023 USD ($)
Income Taxes [Abstract]
Income tax expense	$ 4,007	$ 718	$ 17,712	$ 11,235
Capitalized contract cost, amortization period	15 years		15 years
Unrecognized tax benefits	$ 7,600		$ 7,600			$ 13,026
Unrecognized tax benefits that would impact effective tax rate	$ 7,518		7,518			$ 7,518
Interest or penalties			$ 995	$ 569
Number of subsidiaries | subsidiary			4
ACM Research (Shanghai), Inc. ("ACM Shanghai")
Income Taxes [Abstract]
Foreign corporate tax rate			15%
Foreign Tax Authority
Income Taxes [Abstract]
Foreign corporate tax rate			25%
Effective period of preferential income tax rate			3 years
Foreign Tax Authority | Minimum
Income Taxes [Abstract]
Foreign corporate tax rate			15%
Foreign Tax Authority | Maximum
Income Taxes [Abstract]
Foreign corporate tax rate			25%
Foreign Tax Authority | ACM Research (Shanghai), Inc. ("ACM Shanghai")
Income Taxes [Abstract]
Foreign corporate tax rate					12.50%
Foreign Tax Authority | ACM Research (Shanghai), Inc. ("ACM Shanghai") | Minimum
Income Taxes [Abstract]
Foreign corporate tax rate			15%
Foreign Tax Authority | ACM Research (Wuxi), Inc. ("ACM Wuxi")
Income Taxes [Abstract]
Foreign corporate tax rate			25%
Foreign Tax Authority | ACM Research (Beijing), Inc. ("ACM Beijing")
Income Taxes [Abstract]
Foreign corporate tax rate			25%
Foreign Tax Authority | ACM Research (Lingang), Inc. ("ACM Lingang")
Income Taxes [Abstract]
Foreign corporate tax rate			15%

INCOME TAXES - Summary of Incom

INCOME TAXES - Summary of Income Tax Benefit (Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income Tax Disclosure [Abstract]
Total income tax expense	$ (4,007)	$ (718)	$ (17,712)	$ (11,235)

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Thousands, ¥ in Millions	9 Months Ended
	Sep. 30, 2024 USD ($) legalProceeding	Sep. 30, 2024 CNY (¥)	Sep. 30, 2024 CNY (¥) legalProceeding	Dec. 31, 2023 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Contractual obligation	$ 11,023			$ 30,936
Other commitment	$ 16,737			$ 7,413
Land use rights period	7 years	7 years
Annual total taxes	$ 22,000	¥ 157.6
Security deposit refund percentage	20%		20%
Security deposit	$ 400		¥ 2.5
Number of outstanding legal proceedings | legalProceeding	0		0

SEGMENT INFORMATION (Details)

SEGMENT INFORMATION (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2024 USD ($) segment	Dec. 31, 2023 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment	1
Number of operating segments | segment	1
Geographic Areas, Long-Lived Assets [Abstract]
Long-lived assets	$ 285,451	$ 223,191
Mainland China
Geographic Areas, Long-Lived Assets [Abstract]
Long-lived assets	263,930	209,725
Korea
Geographic Areas, Long-Lived Assets [Abstract]
Long-lived assets	12,497	12,190
United States
Geographic Areas, Long-Lived Assets [Abstract]
Long-lived assets	$ 9,024	$ 1,276

STATUTORY SURPLUS RESERVE (Deta

STATUTORY SURPLUS RESERVE (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Retained Earnings (Accumulated Deficit) [Abstract]
Statutory surplus reserve	$ 30,060	$ 30,060
ACM Research (Shanghai), Inc. ("ACM Shanghai")
Retained Earnings (Accumulated Deficit) [Abstract]
Statutory surplus reserve	$ 30,060	$ 30,060

SUBSEQUENT EVENTS (Details)

SUBSEQUENT EVENTS (Details) - Subsequent Event $ in Thousands	Oct. 21, 2024 USD ($)	Oct. 01, 2024 USD ($) ft²
Subsequent Event [Line Items]
Area for development and production center, total floor space | ft²		39,500
Area for development and production center, space used for clean room | ft²		5,200
Commercial facility agreement, purchase price | $		$ 7,750
Ninebell
Subsequent Event [Line Items]
Equity method investment, aggregate cost | $	$ 16,737
Percent ownership by ACM and subsidiaries	36.40%