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

Rhea-AI Filing Summary

Charles C. Pappis, a director of ACM Research, Inc. (ACMR), was granted a stock option to buy 20,000 shares of Class A common stock at an exercise price of $24.93 per share. The option was granted with an exercise date of 08/12/2025, vests immediately prior to the issuer's 2026 annual meeting subject to continued service, and expires on 08/11/2035. After this transaction, Mr. Pappis beneficially owns 20,000 underlying shares through the option, held directly.

Positive

• Director alignment: 20,000-share option aligns the reporting director's interests with long-term shareholder value
• Retention incentive: Option vests immediately prior to the 2026 annual meeting, encouraging continued service through the vesting date

Negative

• None.

Insights

Corporate Governance Expert

TL;DR: A routine director option grant aligns a director's incentives with shareholders but increases potential share dilution.

The grant of a 20,000-share option to a director is a common component of director compensation designed to align long-term interests with shareholders. The immediate vesting prior to the 2026 annual meeting ties retention to continued service through that date. The 10-year-plus term is typical for equity awards, providing a long window to exercise.

Securities Analyst

TL;DR: Transaction is a standard equity award to a director; it is informational for cap table and governance monitoring.

The option specifics—20,000 shares at $24.93, exercisable as noted and expiring 08/11/2035—should be recorded for outstanding share count and potential dilution schedules. This disclosure does not include market context or indicate other compensation changes, so it is a routine insider filing rather than a materially transformative event.

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^*

Pappis Charles C

(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)
08/12/2025

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

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	$24.93	08/12/2025		A		20,000		(1)	08/11/2035	Class A Common Stock	20,000	$0	20,000	D

Explanation of Responses:

1. The option will vest and become exercisable immediately prior to the 2026 annual meeting of stockholders of the issuer, subject to continued service through the vesting date.

	/s/ Mark McKechnie, Attorney-in-Fact for Charles Pappis	08/14/2025
	** 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 Charles Pappis receive on 08/12/2025?

He received a stock option for 20,000 shares of Class A common stock exercisable at $24.93 per share.

When does the option granted to Charles Pappis vest and expire?

It vests immediately prior to the 2026 annual meeting (subject to continued service) and expires on 08/11/2035.

How many shares will Charles Pappis beneficially own following the reported transaction?

20,000 shares underlying the option are reported as beneficially owned following the transaction.

What is the exercise price of the option granted to the ACMR director?

The exercise price is $24.93 per share.