SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
X	Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person* Wang David H (Last) (First) (Middle) C/O ACM RESEARCH, INC. 42307 OSGOOD ROAD, SUITE I (Street) FREMONT CALIFORNIA 94539 (City) (State) (Zip) UNITED STATES (Country)	2. Issuer Name and Ticker or Trading Symbol ACM Research, Inc. [ ACMR ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director X 10% Owner X Officer (give title below) Other (specify below) See Remarks
	2a. Foreign Trading Symbol
	3. Date of Earliest Transaction (Month/Day/Year) 06/03/2026	6. Individual or Joint/Group Filing (Check Applicable Line) X Form filed by One Reporting Person Form filed by More than One Reporting Person
	4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Class A Common Stock	06/03/2026		M		60,000	A	$1	862,708	D
Class A Common Stock	06/03/2026		S(1)		4,300	D	$87.57(2)	858,408	D
Class A Common Stock	06/03/2026		S(1)		6,295	D	$88.98(3)	852,113	D
Class A Common Stock	06/03/2026		S(1)		32,450	D	$89.84(4)	819,663	D
Class A Common Stock	06/03/2026		S(1)		9,925	D	$90.78(5)	809,738	D
Class A Common Stock	06/03/2026		S(1)		5,843	D	$92.38(6)	803,895	D
Class A Common Stock	06/03/2026		S(1)		1,187	D	$93.04(7)	802,708	D
Class A Common Stock	06/04/2026		M		40,002	A	$1	842,710	D
Class A Common Stock	06/04/2026		S(1)		2,060	D	$83.86(8)	840,650	D
Class A Common Stock	06/04/2026		S(1)		17,543	D	$85.11(9)	823,107	D
Class A Common Stock	06/04/2026		S(1)		10,992	D	$86.07(10)	812,115	D
Class A Common Stock	06/04/2026		S(1)		8,581	D	$87.13(11)	803,534	D
Class A Common Stock	06/04/2026		S(1)		826	D	$87.91(12)	802,708	D
Class A Common Stock								100,002	I	By Jing Chen, wife of David H. Wang
Class A Common Stock								45,837	I	By Sophia Wang, daughter of David H. Wang
Class A Common Stock								180,000	I	By David Hui Wang and Jing Chen Family Irrevocable Trust for Wang Children
Class A Common Stock								620,001	I	By Wang-Chen Family Living Trust

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Option	$1	06/03/2026		M			60,000	(13)	12/27/2026	Class A Common Stock	60,000	$0	310,002	D
Stock Option	$1	06/04/2026		M			40,002	(13)	12/27/2026	Class A Common Stock	40,002	$0	270,000	D

Explanation of Responses:

1. The sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on November 29, 2024.

2. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $87.22 to $88.04, 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), (10), (11), and (12) to this Form 4.

3. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $88.24 to $89.22, inclusive.

4. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $89.24 to $90.22, inclusive.

5. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $90.24 to $91.22, inclusive.

6. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $92.01 to $92.8, inclusive.

7. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $93.02 to $93.39, inclusive.

8. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $83.61 to $84.24, inclusive.

9. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $84.62 to $85.6, inclusive.

10. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $85.7 to $86.57, inclusive.

11. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $86.73 to $87.66, inclusive.

12. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $87.77 to $88.01, inclusive.

13. The option is fully vested and exercisable.

Remarks:

Chief Executive Officer, President and Director

	/s/ Mark McKechnie, Attorney-in-Fact for David H. Wang	06/05/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)