ACM Research, Inc.

(In thousands, except share, percentage and per share data)

NOTE 1 –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.

In September 2025, ACM Shan ghai issued 38.6 million of its ordinary shares in a private offering (the "Private Offering"). As a result of the Private Offering, ACM Research's equity interests in ACM Shanghai declined from 81.1% as of June 30, 2025, to 74.6% as of September 30, 2025.

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

NOTE 2 –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, 2024 included in ACM’s Annual Report on Form 10-K.

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, 2025 and the results of operations for the three and nine months ended September 30, 2025 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 long-term investments, stock-based compensation arrangements, realization of deferred tax assets, uncertain tax positions, assessment for impairment of long-lived assets and long-term investments, allowance for credit losses, inventory valuation, and useful lives of property, plant and equipment.

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, 2025 and December 31, 2024:

The amounts in mainland China do not include short-term and long-term time deposits which in aggregate totaled $30,922 and $30,552 at September 30, 2025 and December 31, 2024, 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 the Company's 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, 2025 and 2024, cash payments from ACM Shanghai and ACM Lingang to ACM California for the procurement of goods and services were $7,500 and $2,335, respectively. For the nine months ended September 30, 2025 and 2024, cash payments from ACM Shanghai and ACM Lingang to ACM California for the procurement of goods and services were $13,683 and $16,734, 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 Hong Kong exceed the Hong Kong Deposit Insurance Corporation insurance limits and are subject to risk of loss. No losses have been experienced to date. There are no additional restrictions for the transfer of cash from bank accounts in the U.S., South Korea, Singapore and Hong Kong.

For the nine months ended September 30, 2025 and 2024 , ACM Shanghai paid $29,238, and $28,480, in dividends, net of taxes, to ACM Research, respectively. ACM Shanghai paid a cash dividend of $7,578 and $6,900 to the non-controlling interest shareholders in the nine months ended September 30, 2025 and 2024, respectively.

For the nine months ended September 30, 2025 and 2024, with the exception of sales and services-related transfer-pricing payments in the ordinary course of business, and dividends paid by ACM Shanghai 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 could be withdrawn before maturity and are presented as short-term deposits and long-term deposits in the accompanying condensed consolidated financial statements based on their expected dates of maturity. They are also subject to the risk control regulatory standards described above upon maturity.

For the three months ended September 30, 2025 and 2024, interest income related to time deposits was $270 and $486, respectively. For the nine months ended September 30, 2025 and 2024, interest income related to time deposits was $749 and $1,732, respectively.

Restricted Cash

As of September 30, 2025, all of the Company's restricted cash was held by financial institutions located in mainland China, Hong Kong and South Korea, and mainly represents cash secured to guarantee delivery of tools.

Fair Value Measurement

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

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

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

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

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

The Company’s financial instruments primarily include its cash, cash equivalents, restricted cash, short term and long term deposits, short-term and long-term investments, other receivables, accounts receivable, accounts payable, and short-term and long-term borrowings. The estimated fair value of cash and cash equivalents, restricted cash, short-term time deposits, accounts receivable, other receivables, accounts payable, and short-term borrowings approximate their respective carrying value due to the short period of time to their maturities. The carrying amounts of long-term time deposits approximate their fair values as the related interest rates currently offered by financial institutions for similar debt instruments of comparable maturities.

All transfers between fair value hierarchy levels are recognized by the Company at the end of each reporting period. In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, an investment’s level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value

measurement in its entirety, requires judgment and considers factors specific to the investment. The inputs or methodology

used for valuing financial instruments are not necessarily an indication of the risks associated with investment in those instruments.

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

The Company did not have any assets and liabilities measured at fair value on a non-recurring basis as of September 30, 2025. 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 thethree and nine months ended September 30, 2025 and 2024.

Refer to note 10 for fair value information related to the Company’s outstanding long-term borrowings as of September 30, 2025 and December 31, 2024.

Basic and Diluted Net Income per Share of Common Stock

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

Basic and diluted net income per share of common stock is presented using thetwo-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 thetwo-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, 2025 and 2024.

ACM Research is authorized to issue Class A and Class B common stock. Thetwo classes of common stock are substantially identical in all material respects, except for voting rights. The net income per share of common stock attributable to each class is the same under the “two-class” method. As such, thetwo 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 potentially 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 stock options exercisable into shares of the Company’s common stock of 655,861 and 1,218,503 for the three and nine months ended September 30, 2025, respectively and 1,397,590 and 887,985 for the three and nine months ended September 30, 2024, 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, 2025 and 2024, two customers accounted for 38.9% and four customers accounted for 62.3% of revenue, respectively. For the nine months ended September 30, 2025 and 2024, four customers accounted for 46.3% and five customers accounted for 56.3% of revenue, respectively.

•Accounts receivable concentration. As of September 30, 2025 and December 31, 2024, five customers accounted for 66.8% and four customers accounted for 57.1%, respectively, of the Company’s accounts receivables. The Company believes that the accounts receivable balances due from these customers do not represent a significant credit risk based on past collection experience.

Recently Issued Accounting Pronouncements Not Yet Adopted

In December 2023, the Financial Accounting Standards Board ("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 impact of this guidance and expects the adoption to result in disclosure changes only.

In December 2024, the FASB issued ASU 2024-03: Income Statement--Reporting Comprehensive Income--Expense Disaggregation Disclosures (Subtopic 220-40), which requires additional disclosures about specific types of expenses included in the expense captions presented on the face of the income statement as well as disclosures about selling expenses. In January 2025, the FASB issued ASU 2025-01, which clarifies the effective date of ASU 2024-03. ASU 2024-03 is effective for fiscal years beginning after December 15, 2026, and interim periods within fiscal years beginning after December 15, 2027. This ASU should be applied prospectively with the option to apply the standard retrospectively. The Company is currently in the process of evaluating the disclosure impact.

In July 2025, the FASB issued ASU 2025-05, Financial Instruments – Credit Losses (Topic 326) Measurement of Credit Losses for Accounts Receivable and Contract Assets, which provides entities with a practical expedient that assumes that current conditions as of the balance sheet date do not change for the remaining life of the asset in developing reasonable and supportable forecasts as part of estimating expected credit losses. ASU 2025-05 is effective for public companies for annual periods beginning after December 15, 2025. Early adoption is permitted. The Company is currently in the process of evaluating the disclosure impact.

In September 2025, the FASB issued ASU 2025-06, Intangibles—Goodwill and Other—Internal-Use Software, which is an update to remove all references to prescriptive and sequential software development stages (referred to as “project stages”). This ASU is effective for all entities for annual reporting periods beginning after December 15, 2027, and interim reporting periods within those annual reporting periods. Early adoption is permitted as of the beginning of an annual reporting period. The Company is currently evaluating the impact that the adoption of ASU 2025-06 may have on its consolidated financial statements.

NOTE 3 –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:

During the three and nine months ended September 30, 2025 and 2024, substantially all of the Group's revenue were derived from customers in mainland China, and therefore no geographical segments are presented.

Contract liabilities balances were as follows as of:

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

NOTE 4 –ACCOUNTS RECEIVABLE, NET

At September 30, 2025 and December 31, 2024, accounts receivable consisted of the following:

The movement of the allowance for credit losses for the nine months ended September 30, 2025 and 2024 is as follows:

The Company assesses collectability by reviewing accounts receivable on a general basis where similar characteristics exist and on an individual basis when the Company identifies specific customers with known disputes or collectability issues. In determining the amount of the allowance for credit losses, the Company considers historical collectability based on past due status, the age of the accounts receivable balances, credit quality of the Company’s customers based on ongoing credit evaluations, current economic conditions, reasonable and supportable forecasts of future economic conditions, and other factors that may affect the Company’s ability to collect from customers.

NOTE 5 –INVENTORIES, NET

At September 30, 2025, and December 31, 2024, inventories consisted of the following:

Raw materials increased by $102,096 for the nine months ended September 30, 2025 based on the Company's production plans and strategic purchases to mitigate supply chain risk.

At September 30, 2025 and December 31, 2024, the value of finished goods inventory, which is comprised of first-tools at customers' physical locations, for which customers were contractually obligated to take ownership upon acceptance totaled $174,367 and $206,018, respectively.

During the three months ended September 30, 2025 and 2024, the provisions for inventory of $4,228 and $849 were recognized in cost of revenue, respectively. During the nine months ended September 30, 2025 and 2024, the provisions for inventory of $9,853 and $3,858 were recognized in cost of revenue, respectively.

NOTE 6 –PROPERTY, PLANT AND EQUIPMENT, NET

At September 30, 2025 and December 31, 2024, property, plant and equipment consisted of the following:

Depreciation expense for the three months ended September 30, 2025 and 2024 was $2,458 and $2,389, respectively. Depreciation expense for the nine months ended September 30, 2025 and 2024 was $8,362 and $7,073, respectively.

Building and plants includes $35,139 for the Lingang housing property which is pledged as security for loans from the China Merchants Bank (note 10).

Construction in progress primarily reflects costs incurred for certain facilities related to improvements of ACM Shanghai's Lingang Development and Production Center.

NOTE 7 –OTHER LONG-TERM ASSETS

NOTE 8 –SHORT-TERM BORROWINGS

At September 30, 2025 and December 31, 2024, short-term borrowings consisted of the following:

Certain covenants for the $14,078 short-term facility of Bank of China require ACM Shanghai’s year-end outstanding interest-bearing debt not to exceed five times of its annual EBITDA, and to comply with other non-financial covenants, or Bank of China has the right to suspend the facility, or request ACM Shanghai to accelerate repayment or provide credit enhancement.

NOTE 9 –OTHER PAYABLES AND ACCRUED EXPENSES

At September 30, 2025 and December 31, 2024, other payables and accrued expenses consisted of the following:

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:

NOTE 10 –LONG-TERM BORROWINGS

At September 30, 2025 and December 31, 2024, long-term borrowings consistedof the following:

In June 2025, ACM Shanghai entered into a long-term loan facility of $5,628 from Bank of China and drew down the full amount. Principal repayments shall be made in 6 installments beginning June 2025, with final maturity in June 2028. Certain covenants for the facility require ACM Shanghai’s year-end outstanding interest-bearing debt not toexceed five timesofits annual EBITDA, and to comply with other non-financial covenants, or Bank of China has the right to suspend the facility, or request ACM Shanghai to accelerate repayment or provide credit enhancement.

In January 2025, ACM Research entered into a long-term loan facility of $281,400 from China CITIC Bank, of which it drew the full amount. Principal repayments shall be made in 6 installments beginning January 2025, with final maturity in January 2028.

In November 2024, ACM Shanghai entered into a long-term loan facility of $42,210 from Industrial and Commercial Bank of China for the purpose of funding its working capital and drew down the full amount. Principal repayment shall be made in 6 installments beginning May 2025, with final maturity in November 2027.

In November 2024, ACM Shanghai entered into a long-term loan facility of $140,700 from Bank of China for its project expen ditures and drew down $6,673 under this facility. Principal repay ment shall be made in 12 installments until December 2028, with final maturity in June 2034. Certain covenants for the facility require ACM Shanghai’s year-end outstanding interest-bearing debt notto exceed five times its annual EBITDA, and to comply with other non-financial covenants, or Bank of China has the right to suspend the facility, or request ACM Shanghai to accelerate repayment or provide credit enhancement.

In August 2024, ACM Shanghai entered into a long-term loan facility, of $140,700, from China Merchants Bank for project expenditures and drew down $8,232 under this facility. Certain covenants for the facility require ACM Shanghai to either repay 50% of the outstanding principal withintwo months, or repay the loan in accordance with revised payment schedule, if ACM Shanghai does not complete, within three years after the initial drawdown, or before January 2028, a Private Offering with more than RMB 900,000 of proceeds.

In April 2024, ACM Lingang entered into a long-term loan facility of $42,210 from the Agricultural Bank of China. ACM Shanghai drew down $13,161 in 2024 and further drew down $29,049 under this facility in the nine months ended September 30, 2025. Principal repayments shall be made in 18 installments beginning November 2025, with final maturity in April 2034.

As of September 30, 2025 and December 31, 2024, the total carrying amount of long-term loans was $241,993 and $149,997, compared with an estimated fair value of $225,396 and $141,264, 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 loans, including the current portion, as of September 30, 2025 are as follows:

NOTE 11 –LONG-TERM INVESTMENTS

On April 22, 2024, ACM Shanghai entered into an investment agreement with Ninebell Co., Ltd. ("Ninebell") to acquire 20% of its equity interests. In December 2024, ACM Shanghai paid total consideration of $16,737. The share certificate was issued on January 1, 2025. After the share purchase transaction closed on January 1, 2025, the Company owned 36.2% equity interests of Ninebell. Subsequent to the Private Offering during 2025, the Company's equity interests in Ninebell decreased to 34.9% as of September 30, 2025.

The Company’s long-term investment balance primarily consisted of the following:

The Company’s long-term investment balance consisted of the following:

NOTE 12 –SHORT-TERM INVESTMENTS

At September 30, 2025 and December 31, 2024, the components of short-term investments were as follows:

For the three and nine months ended September 30, 2025 and 2024, the net gains (losses) recognized on equity securities were as follows:

For thethree and nine months ended September 30, 2025, the Company received dividends of $0 and $54 from short-term investments.

For the three and nine months ended September 30, 2024, the Company recognized a realized gain of $171 and $444 in proceeds from the sale of short-term investments.

NOTE 13 –RELATED PARTY BALANCES AND TRANSACTIONS

Ninebell

Ninebell is an equity investee of ACM and ACM Shanghai (note 11) and is the Company’s principal supplier of robotic delivery system subassemblies used in 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 to pay the remaining amounts upon receipt of the product.

Shengyi

Shengyi is an equity investee of ACM Shanghai (note 11) 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 to pay the remaining amount 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 the Company’s condensed consolidated financial statements:

NOTE 14 –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 toone vote, and each share of Class B common stock is entitled totwenty votes and is convertible at any time intoone 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.

At September 30, 2025 and December 31, 2024, the number of shares of Class A common stock issued and outstanding was 59,854,640 and 57,938,885, respectively.

At September 30, 2025 and December 31, 2024, the number of shares of Class B common stock issued and outstanding was 5,021,811 and 5,021,811, respectively.

NOTE 15 –STOCK-BASED COMPENSATION

During the nine months ended September 30, 2025, the Company issued option grants for 242,000 shares to employees and board members under its 2016 Omnibus Incentive Plan. The share-based awards are accounted for as equity awards, are only subject to service vesting conditions, and vest over a period of 4 years for employees and 0.25 year for board members. The Company did not grant any non-employee stock options during the nine months ended September 30, 2025.

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

(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 benil as ACM has no history or expectation of paying a dividend on its Class A common stock.

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

NOTE 16 –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.

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 had total unrecognized tax benefits of $16,774 as of September 30, 2025 and December 31, 2024. The Company does 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, 2025 and 2024, $3,379 and $677 of interest and penalties were recognized, respectively.

The Company’s effective tax rate differs from statutory rates of 21% for U.S. federal income tax purposes and 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), global intangible low-taxed income (GILTI) inclusions, and R&D super deduction. As a result, the Company recorded income tax expense of $6,733 and $17,712 during the nine months ended September 30, 2025 and 2024, respectively. The decrease in the Company's effective income tax rate for the nine months ended September 30, 2025 compared to the same period of the prior year was primarily due to a lower estimated effective tax rate for ACM Shanghai and other factors.

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 files income tax returns in the United States and 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 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 25%, respectively. Pursuant to the Corporate Income Tax Law of mainland China, the Company's mainland China subsidiaries generally would be liable for mainland China corporate income taxes at 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, 2021, and 2024 effective until December 31, 2026.

NOTE 17 –COMMITMENTS AND CONTINGENCIES

As of September 30, 2025, the Company had $2,126 of open capital commitments to construction contracts.

Covenants in ACM Lingang’s Grant Contract for State-owned Construction Land Use Right in Shanghai City (Category of R&D Headquarters and Industrial Projects) with the China (Shanghai) Pilot Free Trade Zone Lingang Special Area Administration require, among other things, that ACM Lingang pay liquidated damages in the event that within 6 years after the land use right is obtained in July 2020, 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.

Legal Matters

In the normal course of business, the Company is subject to contingencies, including legal proceedings, investigations, and environmental claims arising out of the normal course of business 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.

In 2025, ACM's subsidiary, ACM Korea, received inquiries from the Seoul Customs Office regarding certain goods produced and shipped by ACM Korea to overseas markets. ACM Korea is fully cooperating, and has responded to follow-up requests for additional information. The investigation is on-going and in its preliminary stages, and as such, this matter is subject to uncertainties and further developments as it proceeds. Although the Company cannot predict the outcome of this, or any other related governmental inquiries or proceedings that may occur, the Company does not believe at this time it will have a material effect on its consolidated financial condition or results of operations.

The Company’s management has evaluated all other proceedings and claims that existed as of September 30, 2025. In the opinion of management, except with respect to the ACM Korea customs matter described above, no provision for liability nor disclosure was required as of September 30, 2025 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, 2025, the Company hadno material outstanding legal proceedings.

NOTE 18 –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 development, 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 intoone reportable segment.

The CODM assesses financial performance for the Company and decides how to allocate resources based on consolidated revenue, gross margin and income from operations. The CODM considers forecasts and actual results on a regular basis when assessing the operating results and making resource decisions. The allocation decisions include top down targets for research and development, sales and marketing, and general and administration expenses, and also specific budgets for research and development on new product initiatives, or sales and marketing to target specific customer or geographic regions.

Significant expenses within income from operations, as well as within net income, include consolidated cost of revenue, sales and marketing, research and development, and general and administrative, and which are each separately presented in the Company’s condensed consolidated statements of comprehensive income. Other segment items within net income include interest income, interest expense, income (loss) from equity method investments and other expense, net, which are each separately presented on the Company’s condensed consolidated statements of comprehensive income.

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, and right-of-use assets and are attributed to the geographic location in which the respective asset is located.

Long-lived assets by geographic region were as follows:

NOTE 19 –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 $30,514 as of both

September 30, 2025 and December 31, 2024, and is presented as statutory surplus reserve on the Company’s condensed consolidated balance sheets.