X0508 4 2025-05-14 0001680062 ACM Research, Inc. ACMR 0001775007 McKechnie Mark C/O ACM RESEARCH, INC. 42307 OSGOOD ROAD, SUITE I FREMONT CA 94539 true See Remarks true Class A Common Stock 2025-05-14 4 M 0 15000 5.6 A 15900 D Class A Common Stock 2025-05-14 4 S 0 15000 25.22 D 900 D Stock Option 5.6 2025-05-14 4 M 0 15000 0 D 2029-04-22 Class A Common Stock 15000 0 D The sale reported on this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 7, 2024. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $25.02 to $25.38, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnote (2) to this Form 4. The option is fully vested and exercisable. Chief Financial Officer and Treasurer /s/ Mark McKechnie 2025-05-16