ACM Research, Inc.

On September 4, 2025, Howard Chen, Legal Counsel, adopted a Rule 10b5-1 trading arrangement (the “Chen Plan”) that is intended to satisfy the affirmative defense of Rule 10b5-1(c) of the Exchange Act. The Chen Plan allows for the contemporaneous exercise of options and sale of up to 50,000 shares of Class A Common Stock, at specific market prices, commencing on December 5, 2025, and continuing until (i) all such options are exercised and the underlying shares are sold, (ii)November 13, 2026, or (iii) such date that the Chen Plan is otherwise terminated according to its terms, whichever comes first.

On August 28, 2025, Fuping Chen, Vice President, Sales—China of ACM Research (Shanghai), Inc., adopted a Rule 10b5-1 trading arrangement (the “Fuping Chen Plan”) that is intended to satisfy the affirmative defense of Rule 10b5-1(c) of the Exchange Act. The Fuping Chen Plan allows for the contemporaneous exercise of options and sale of up to 120,000 shares of Class A Common Stock, at specific market prices, commencing on December 2, 2025, and continuing until (i) all such options are exercised and the underlying shares are sold, (ii)November 20, 2026, or (iii) such date that the Fuping Chen Plan is otherwise terminated according to its terms, whichever comes first.

On August 27, 2025, Mark McKechnie, Chief Financial Officer, adopted a Rule 10b5-1 trading arrangement (the “McKechnie Plan”) that is intended to satisfy the affirmative defense of Rule 10b5-1(c) of the Exchange Act. The McKechnie Plan allows for the contemporaneous exercise of options and sale of up to 129,801 shares of Class A Common Stock, at specific market prices, commencing on December 4, 2025, and continuing until (i) all such options are exercised and the underlying shares are sold, (ii)May 10, 2027, or (iii) such date that the McKechnie Plan is otherwise terminated according to its terms, whichever comes first.

On August 13, 2025, Haiping Dun, Board Member of ACM Research, adopted a Rule 10b5-1 trading arrangement (the “Dun Plan”) that is intended to satisfy the affirmative defense of Rule 10b5-1(c) of the Exchange Act. The Dun Plan allows for the contemporaneous exercise of options and sale of up to 30,000 shares of Class A Common Stock, at specific market prices, commencing on March 9, 2026, and continuing until (i) all such options are exercised and the underlying shares are sold, (ii)August 13, 2027, or (iii) such date that the Dun Plan is otherwise terminated according to its terms, whichever comes first.

On August 13, 2025, Lisa Feng, Chief Financial Officer of ACM Shanghai, adopted a Rule 10b5-1 trading arrangement (the “Feng Plan”) that is intended to satisfy the affirmative defense of Rule 10b5-1(c) of the Exchange Act. The Feng Plan allows for the contemporaneous exercise of options and sale of up to 30,000 shares of Class A Common Stock, at specific market prices, commencing on November 12, 2025, and continuing until (i) all such options are exercised and the underlying shares are sold, (ii)November 13, 2026, or (iii) such date that the Feng Plan is otherwise terminated according to its terms, whichever comes first.