UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Title of Each Class Trading Symbol Name of Each Exchange on which Registered Class A Common Stock, $0.0001 par value ACMR Nasdaq Global Market Emerging growth company ☑ FORM 10‑K (Mark One) ☑ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2019 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period ...