X0508 4 2025-11-12 0001680062 ACM Research, Inc. ACMR 0001721581 Dun Haiping C/O ACM RESEARCH, INC. 42307 OSGOOD ROAD, SUITE I FREMONT CA 94539 true false Class A Common Stock 2025-11-12 4 G 0 755090 0 D 0 D Class A Common Stock 755090 I Haiping Dun & Chi-Pin H Dun Revocable Trust Reflects a gift of 755,090 shares of Class A common stock from the reporting person to the Haiping Dun & Chi-Pin H Dun Revocable Trust, of which the reporting person is co-trustee and of which the reporting person's immediate family members are beneficiaries. /s/ Mark McKechnie, Attorney-in-Fact for Haiping Dun 2025-11-14