Form 4 Filing for ACM Research, Inc. - Officer Transactions

This filing details stock transactions by Cheav Sotheara, Senior Vice President of Manufacturing at ACM Research (Shanghai), Inc. On June 4, 2026, Sotheara acquired 13,351 shares of Class A Common Stock at \$13.89 per share and exercised stock options for 13,351 shares. The same day, 1300 shares were sold at a weighted average of \$84.08, 9212 shares at \$85.11, and 2839 shares at \$85.77. On June 5, 2026, an additional 5,399 shares were acquired at \$13.89, and stock options for 5,399 shares were exercised. Subsequent sales on June 5 included 2,384 shares at \$81.73, 968 shares at \$82.61, 400 shares at \$84.01, and 1,647 shares at \$85.41. All sales were conducted under a Rule 10b5-1 trading plan. Post-transaction, Sotheara holds 100,002 shares of Class A Common Stock and has 37,500 vested stock options remaining.