ACM Research, Inc.

On May 21, 2026, Mark McKechnie, Chief Financial Officer of ACM Research, Inc., 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 105,199 shares of Class A Common Stock, at specific market prices, commencing on August 20, 2026, and continuing until (i) all such options are exercised and the underlying shares are sold, (ii)May 19, 2028, or (iii) such date that the McKechnie Plan is otherwise terminated according to its terms, whichever comes first.

On June 5, 2026, Hui Wang, Chief Executive Officer of ACM Research, Inc. adopted a Rule 10b5-1 trading arrangement (the “Wang Plan”) that is intended to satisfy the affirmative defense of Rule 10b5-1(c) of the Exchange Act. The Wang Plan allows for the contemporaneous exercise of options and sale of up to 270,000 shares of Class A Common Stock, at specific market prices, commencing on September 8, 2026, and continuing until (i) all such options are exercised and the underlying shares are sold, (ii)November 30, 2026, or (iii) such date that the Wang Plan is otherwise terminated according to its terms, whichever comes first.

On June 8, 2026, Sotheara Cheav, Senior Vice President, Manufacturing of ACM Research, Inc., adopted a Rule 10b5-1 trading arrangement (the “Cheav Plan”) that is intended to satisfy the affirmative defense of Rule 10b5-1(c) of the Exchange Act. The Cheav Plan allows for the contemporaneous exercise of options and sale of up to 13,750 shares of Class A Common Stock, at specific market prices, commencing on September 8, 2026, and continuing until (i) all such options are exercised and the underlying shares are sold, (ii)September 9, 2027, or (iii) such date that the Cheav Plan is otherwise terminated according to its terms, whichever comes first.

On June 15, 2026, Lisa Feng, Chief Executive Officer of ACM Shanghai, Inc. 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 7,596 shares of Class A Common Stock, at specific market prices, commencing on September 14, 2026, and continuing until (i) all such options are exercised and the underlying shares are sold, (ii)September 14, 2027, or (iii) such date that the Feng Plan is otherwise terminated according to its terms, whichever comes first.