X0306 4 2018-01-31 0001680062 ACM Research, Inc. ACMR 0001721376 Chen Fufa C/O ACM RESEARCH, INC. 42307 OSGOOD ROAD, SUITE I FREMONT CA 94539 true See Remarks Class A Common Stock 2018-01-31 4 M false 33334 0.75 A 106668 D Class A Common Stock 2018-01-31 4 M false 22915 1.50 A 129583 D Stock Option 0.75 2018-01-31 4 M false 33334 0 D 2021-05-01 Class A Common Stock 33334 0 D Stock Option 1.50 2018-01-31 4 M false 22915 0 D 2025-05-01 Class A Common Stock 22915 10419 D On January 31, 2018, the reporting person exercised previously issued stock options to purchase 33,334 shares of Class A Common Stock of the Issuer. On January 31, 2018, the reporting person exercised previously issued stock options to purchase 22,915 shares of Class A Common Stock of the Issuer. The option was fully vested and exercisable. The option vested and became exercisable as to 8,333 shares on May 1, 2016 and the remaining 25,001 shares vest and become exercisable in equal monthly installments over the following 36 months, subject to continued service through each vesting date. Vice President, Marketing of ACM Research (Shanghai), Inc., a subsidiary of the Issuer /s/ Mark L. Johnson, Attorney-in-Fact for Fufa Chen 2018-05-17