ACM Research Inc-A美股招股说明书(2026-05-12版)

2,884,615 Shares of ClassA Common Stock We are offering to certain institutional and accredited investors (the “Investors”) 2,884,615 shares of ClassAcommon stock, $0.0001 par value per share (the “ClassA Common Stock”), of the Company, at the offering priceof $52.00 per share, in a registered direct offering pursuant this prospectus supplement and the accompanyingprospectus and a securities purchase agreement dated May 12, 2026, by between the Company and the Investors(the “Purchase Agreement”). Our ClassA Common Stock is listed on the Nasdaq Global Market under the symbol “ACMR.” The last reportedsale price of our ClassA Common Stock on the Nasdaq Global Market on May 11, 2026 was $64.67 per share. Investing in our ClassA Common Stock involves a high degree of risk. You should carefully read andconsider this prospectus supplement, the accompanying prospectus, the documents incorporated byreference herein and therein, and the risk factors described in, and incorporated by reference under, “RiskFactors” beginning on page S-4of this prospectus supplement, and under similar headings in the otherdocuments in the other documents incorporated by reference herein before investing in any securities. Neither the Securities and Exchange Commission nor any state securities commission has approved ordisapproved of these securities or determined if this prospectus is truthful or complete. Any representationto the contrary is a criminal offense. Delivery of the ClassA Common Stock is expected to be made on or about May 15, 2026, subject to customaryclosing conditions. TABLE OF CONTENTS Prospectus Supplement PageABOUT THIS PROSPECTUS SUPPLEMENTS-1PROSPECTUS SUPPLEMENT SUMMARYS-2THE OFFERINGS-3RISK FACTORSS-4CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTSS-7USE OF PROCEEDSS-9DIVIDEND POLICYS-10PLAN OF DISTRIBUTIONS-11LEGAL MATTERSS-12EXPERTSS-12WHERE YOU CAN FIND MORE INFORMATIONS-13INCORPORATION OF CERTAIN INFORMATION BY REFERENCES-14 TABLE OF CONTENTS ABOUT THIS PROSPECTUS SUPPLEMENT This prospectus supplement and the accompanying prospectus are part of a registration statement that we have filedwith the United States Securities and Exchange Commission, or SEC, utilizing a “shelf” registration process. We provide information to you about this offering of shares of our ClassA Common Stock in two separatedocuments that are bound together: (1) this prospectus supplement, which describes the specific terms and detailsregarding this offering and also adds to and updates information contained in the accompanying prospectus and thedocuments incorporated by reference therein; and (2) the accompanying base prospectus, which provides generalinformation, some of which may not apply to this offering. Generally, when we refer to this “prospectus,” we arereferring to both documents combined. If information in this prospectus supplement is inconsistent with theaccompanying base prospectus, you should rely on this prospectus supplement. However, if any statement in one ofthese documents is inconsistent with a statement in a document having a later date incorporated by reference in thisprospectus supplement, the statement in the document incorporated by reference modifies or supersedes the earlierstatement as our business, financial condition, results of operations and prospects may have changed since the earlierdates. You should rely only on the information contained in, or incorporated by reference into, this prospectus supplement,the accompanying prospectus or in any other prospectus supplement or free writing prospectus that we mayauthorize for use in connection with this offering. We have not authorized any other person to provide you withdifferent or additional information. If anyone provides you with different, additional or inconsistent information, youshould not rely on it. We are not making an offer to sell or soliciting an offer to buy our securities in any jurisdictionin which an offer or solicitation is not authorized or in which the person making that offer or solicitation is notqualified to do so or to anyone to whom it is unlawful to make an offer or solicitation. You should assume that theinformation appearing in this prospectus supplement, the base prospectus, the documents incorporated by referenceinto this prospectus supplement and the base prospectus, and in any free writing prospectus that we may authorizefor use in connection with this offering, is accurate only as of the date of those respective documents. Our business,financial condition, results of operations and prospects may have changed since those dates. You should read thisprospectus supplement, the accompanying prospectus, the documents incorporated by reference herein and therein,and any free writing prospectus that we may authorize for use in connection with this offering, in their entiretybefore making an investment decision. You should also read and consider the information in the documents to whichwe have referred you in the section