SEC Form 4 · accession 0001140361-26-036191

ACM Research, Inc. · ACMR

Statement of changes in beneficial ownership, as filed. Original on EDGAR ↗

Reporting owner

David H Wang

Officer — See Remarks · Director · 10% Owner

Period of report

Sep 8, 2026

Accepted (ET)

Sep 10, 2026 · 4:30 pm EDT

Rule 10b5-1 plan

yes — trade under a plan

Issuer CIK

0001680062

Table I — non-derivative securities

Security	Date	Code	Shares	Price	A/D	Owned after	D/I	Nature of ownership
Class A Common Stock	Sep 8, 2026	M	70,000	$1.00	A	872,708	D
Class A Common Stock^F2	Sep 8, 2026	S	4,803	$75.99	D	867,905	D
Class A Common Stock^F3	Sep 8, 2026	S	51,374	$77.15	D	816,531	D
Class A Common Stock^F4	Sep 8, 2026	S	12,323	$78.08	D	804,208	D
Class A Common Stock^F5	Sep 8, 2026	S	1,500	$78.57	D	802,708	D
Class A Common Stock	Sep 9, 2026	M	70,000	$1.00	A	872,708	D
Class A Common Stock^F6	Sep 9, 2026	S	33,493	$73.80	D	839,215	D
Class A Common Stock^F7	Sep 9, 2026	S	18,934	$74.67	D	820,281	D
Class A Common Stock^F8	Sep 9, 2026	S	11,666	$75.58	D	808,615	D
Class A Common Stock^F9	Sep 9, 2026	S	4,807	$76.73	D	803,808	D
Class A Common Stock^F10	Sep 9, 2026	S	1,100	$77.59	D	802,708	D
Class A Common Stock	holding	—	—		—	100,002	I	By Jing Chen, wife of David H. Wang
Class A Common Stock	holding	—	—		—	180,000	I	By David Hui Wang and Jing Chen Family Irrevocable Trust for Wang Children
Class A Common Stock	holding	—	—		—	620,001	I	By Wang-Chen Family Living Trust

Table II — derivative securities

Security	Conv. / exercise price	Date	Code	Shares	A/D	Exercisable	Expires	Underlying	Underlying shares	Owned after	D/I
Stock Option^F11	$1.00	Sep 8, 2026	M	70,000	D	—	Dec 27, 2026	Class A Common Stock	70,000	200,000	D
Stock Option^F11	$1.00	Sep 9, 2026	M	70,000	D	—	Dec 27, 2026	Class A Common Stock	70,000	130,000	D

Explanation of responses

F1The sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on June 5, 2026.
F10The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $77.59 to $77.59, inclusive.
F11The option is fully vested and exercisable.
F2The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $75.52 to $76.41, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnote (2), (3), (4), (5), (6), (7), (8), (9), and (10) to this Form 4.
F3The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $76.52 to $77.5, inclusive.
F4The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $77.52 to $78.48, inclusive.
F5The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $78.55 to $78.64, inclusive.
F6The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $73.26 to $74.21, inclusive.
F7The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $74.26 to $75.22, inclusive.
F8The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $75.28 to $75.95, inclusive.
F9The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $76.38 to $77.35, inclusive.