ACM Research Inc

On August 13, 2024, Sotheara Cheav, Senior Vice President, Manufacturing of ACM Shanghai, 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 22,598 shares of Class A Common Stock, at specific market prices, commencing on November 13, 2024, and continuing until (i) all such options are exercised and the underlying shares are sold, (ii)March 31, 2025, or (iii) such date that the Cheav Plan is otherwise terminated according to its terms, whichever comes first.

On August 13, 2024, David Wang, President, Chief Executive Officer and a member of the Board of Directors of ACM Research, amended a prior Rule 10b5-1 trading arrangement which was entered into on May 14, 2024, and is considered to have terminated such prior Rule 10b5-1 trading arrangement and established a new Rule 10b5-1 trading arrangement (the “Wang Plan”). The Wang Plan allows for the contemporaneous exercise of options and sale of up to 300,000 shares of Class A Common Stock, at specific market prices, commencing on November 22, 2024, and continuing until (i) all such options are exercised and the underlying shares are sold, (ii)April 30, 2025, or (iii) such date that the Wang Plan is otherwise terminated according to its terms, whichever comes first.