[Form 4] ACM Research, Inc. Insider Trading Activity

Rhea-AI Filing Summary

ACM Research (ACMR) director Haiping Dun filed a Form 4 reporting a charitable-style transfer. On 11/12/2025, he made a gift of 755,090 shares of Class A common stock (transaction code G) at $0 to the Haiping Dun & Chi-Pin H Dun Revocable Trust, where he serves as co‑trustee and immediate family members are beneficiaries.

Following the transaction, reported holdings shifted to 0 shares direct and 755,090 shares indirect via the trust. This filing reflects a change in form of ownership, not an open-market sale.

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

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

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^*

Dun Haiping

(Last) (First) (Middle)

C/O ACM RESEARCH, INC.

42307 OSGOOD ROAD, SUITE I

(Street)

FREMONT CA 94539

(City) (State) (Zip)

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		10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
11/12/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

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	11/12/2025		G(1)		755,090	D	$0	0	D
Class A Common Stock								755,090	I	Haiping Dun & Chi-Pin H Dun Revocable 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

Explanation of Responses:

1. Reflects a gift of 755,090 shares of Class A common stock from the reporting person to the Haiping Dun & Chi-Pin H Dun Revocable Trust, of which the reporting person is co-trustee and of which the reporting person's immediate family members are beneficiaries.

	/s/ Mark McKechnie, Attorney-in-Fact for Haiping Dun	11/14/2025
	** 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.

FAQ

What did ACMR director Haiping Dun report on Form 4?

He reported a gift of 755,090 Class A shares on 11/12/2025 to a revocable trust.

What was the transaction code and price?

The transaction code was G (gift) and the price was $0.

How did Haiping Dun’s ownership change after the transaction?

Reported holdings became 0 shares direct and 755,090 shares indirect via the trust.

Who are the beneficiaries of the trust receiving the shares?

The trust’s beneficiaries are the reporting person’s immediate family members.

Does the filing indicate an open-market sale of ACMR shares?

No. It reflects a gift and a shift from direct to indirect ownership, not a market sale.

What is the relationship of the reporting person to ACM Research?

He is a Director of ACM Research, Inc.