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

Rhea-AI Filing Summary

Tracy Liu, a director of ACM Research, Inc. (ACMR), exercised 15,000 fully vested stock options on September 17, 2025, at a $1 exercise price, creating 15,000 shares of Class A common stock. The same day, the reporting person sold 15,000 shares at $33.00 per share pursuant to a Rule 10b5-1 trading plan adopted March 6, 2025. After these transactions, Ms. Liu beneficially owned 110,772 shares of Class A common stock. The Form 4 was signed by an attorney-in-fact on behalf of Ms. Liu on September 19, 2025.

Positive

• Exercise of fully vested option for 15,000 shares at a $1 exercise price is clearly disclosed
• Sale executed under a Rule 10b5-1 trading plan adopted March 6, 2025, indicating pre-arranged execution
• Post-transaction beneficial ownership reported as 110,772 shares, providing transparency

Negative

• Immediate sale of 15,000 shares at $33.00 reduces the director's reported shareholdings by that amount

Insights

Securities Analyst

TL;DR: Routine option exercise paired with a planned Rule 10b5-1 sale; results in unchanged net economic exposure after the transactions.

The filing documents an exercise of a previously issued, fully vested option for 15,000 shares at $1 per share and an immediate sale of those 15,000 shares at $33.00 per share under a 10b5-1 plan adopted March 6, 2025. Reported beneficial ownership following the transactions is 110,772 shares. This is a standard disclosure for an insider converting options into stock and liquidating shares through a pre-established trading plan; the Form 4 provides clear execution and ownership figures without additional qualifiers.

Corporate Governance Expert

TL;DR: Disclosure is complete and indicates use of a pre-arranged trading plan; no governance red flags in the filing itself.

The Form 4 states the sale was effected pursuant to a Rule 10b5-1 trading plan adopted March 6, 2025, and confirms the option exercised was fully vested and exercisable. The signature is provided by an attorney-in-fact, consistent with authorized filing procedures. The document contains specific transaction dates, prices, and post-transaction beneficial ownership, satisfying standard Section 16 reporting requirements.

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
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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).

1. Name and Address of Reporting Person^*

Liu Tracy

(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)
09/17/2025

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	09/17/2025		M(1)		15,000	A	$1	125,772	D
Class A Common Stock	09/17/2025		S(2)		15,000	D	$33	110,772	D

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	09/17/2025		M(1)			15,000	(3)	12/27/2026	Class A Common Stock	15,000	$0	60,000	D

Explanation of Responses:

1. On September 17, 2025, the reporting person exercised a previously issued stock option to purchase 15,000 shares of Class A Common Stock of the Issuer.

2. The sale reported on this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 6, 2025.

3. The option is fully vested and exercisable.

	/s/ Mark McKechnie, Attorney-in-Fact for Tracy Liu	09/19/2025
	** 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 Tracy Liu report on the Form 4 for ACMR?

Answer: Ms. Liu reported exercising 15,000 stock options at a $1 exercise price and selling 15,000 Class A shares at $33.00 on 09/17/2025.

How many ACMR shares does Tracy Liu beneficially own after the transactions?

Answer: The Form 4 reports Ms. Liu beneficially owns 110,772 shares of Class A common stock following the transactions.

Was the sale of ACMR shares part of a pre-arranged plan?

Answer: Yes. The sale was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 6, 2025.

What price was received for the sold ACMR shares?

Answer: The 15,000 shares were sold at $33.00 per share on 09/17/2025.

Were the exercised options fully vested?

Answer: Yes. The Form 4 states the option exercised is fully vested and exercisable.