ACM Research, Inc.

On November 20, 2025, Charles Pappis , a member of the Board of Directors of ACM Research, adopted a Rule 10b5-1 trading arrangement (the “Pappis Plan”) that is intended to satisfy the affirmative defense of Rule 10b5-1(c) of the Exchange Act. The Pappis Plan allows for the contemporaneous exercise of options and sale of up to 10,000 shares of Class A Common Stock, at specific market prices, commencing on March 3, 2026, and continuing until (i) all such options are exercised and the underlying shares are sold, (ii)March 3, 2027, or (iii) such date that the Pappis Plan is otherwise terminated according to its terms, whichever comes first.

On December 2, 2025, Lisa Feng, Chief Financial Officer of ACM Shanghai, t, 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 March 5, 2026, and continuing until (i) all such options are exercised and the underlying shares are sold, (ii)March 4, 2027, or (iii) such date that the Feng Plan is otherwise terminated according to its terms, whichever comes first.

On December 4, 2025, Tracy Liu , amember of the Board of Directors of ACM Research, adopted a Rule 10b5-1 trading arrangement (the “Liu Plan”) that is intended to satisfy the affirmative defense of Rule 10b5-1(c) of the Exchange Act. The Liu Plan allows for the contemporaneous exercise of options and sale of up to 60,000 shares of Class A Common Stock, at specific market prices, commencing on March 10, 2026, and continuing until (i) all such options are exercised and the underlying shares are sold, (ii)December 15, 2026, or (iii) such date that the Liu Plan is otherwise terminated according to its terms, whichever comes first.