SEC ownership of ACM Research, Inc.

Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001680062.

Comparable stake leader

BlackRock, Inc.

Disclosed value leader

VANGUARD PORTFOLIO MANAGEMENT LLC

Comparable rows

50/50

Latest evidence

30 Jun 2026

Top shareholders Insider holders Latest transactions

Public ticker: ACMR on Nasdaq
Parsed ownership sources: 13F, 13D/G, and 3/4/5
Source: Parsed SEC ownership filingsUse: Compare filing families carefully
Largest SEC-reported holder: BlackRock, Inc.
Ranking: Comparable ownership first, then disclosed value
Comparable ownership rows: 50 of 50
Meaning: Rows with safely comparable ownership %
Latest 13D/G holder: BlackRock, Inc.
Source: Latest parsed Schedule 13D/G stake
Latest parsed ownership date: 30 Jun 2026
Freshness: Most recent filing date in this holder set
Issuer CIK: 0001680062
Issuer location: Fremont, CA

Ownership snapshot

Top shareholders of ACM Research, Inc. (13F + 13D/G + 3/4/5)

Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.

Comparable stake leader

BlackRock, Inc.

Disclosed value leader

VANGUARD PORTFOLIO MANAGE...

Comparable rows

50/50

Latest evidence

30 Jun 2026

13F 13D/G 3/4/5 Lead comparable stake: 13% 13D/G row: BlackRock, Inc. Showing 1-8 of 50 holder rows.

Quick read

BlackRock, Inc. leads the comparable SEC ownership view at 13%.

50 of 50 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.

Open SEC evidence Opens BlackRock, Inc.'s linked filing trail.

Comparable ownership Top 5

BlackRock, Inc. 13%

VANGUARD PORTFOLIO MANAGEMENT LLC 5.3%

Yiheng Capital Management, L.P. 1.2%

Jian Wang 0.39%

Tracy Liu 0.17%

Ownership % is shown only when SEC disclosures are safely comparable across share classes.

Detailed SEC evidence table Showing 1-8 of 50 holder rows

Holder	Evidence	Ownership %	Position	12M Net Δ	As of
BlackRock, Inc.	13F 13D/G Company 13F 13D/G	13% from 13D/G	$314,203,729 7,984,847 shares	—	31 Mar 2026
VANGUARD PORTFOLIO MANAGEMENT LLC	13D/G 13F Vanguard Portfolio Management · Company 13D/G 13F	5.3%	$332,918,191 3,405,116 shares	$0	30 Jun 2026
Yiheng Capital Management, L.P.	13D/G Yiheng Capital Partners, L.P. 13D/G	1.2%	$14,145,634 666,304 shares	$0	30 Sep 2024
Jian Wang	3/4/5 Chief Executive Officer and President of ACM Research (Shanghai), Inc., a subsidiary of the Issuer 3/4/5	0.39%	$8,860,530 253,158 shares	-$2,910,000	18 Sep 2025
Tracy Liu	3/4/5 Director 3/4/5	0.17%	$5,344,749 110,772 shares	-$3,345,782	10 Mar 2026
Lisa Feng	3/4/5 Chief Financial Officer of ACM Research (Shanghai), Inc., a subsidiary of the Issuer 3/4/5	0.08%	$2,329,046 50,001 shares	-$2,439,241	05 Mar 2026
VANGUARD CAPITAL MANAGEMENT LLC	13F Company 13F	3.5%	$89,101,661 2,264,337 shares	—	31 Mar 2026
STATE STREET CORP	13F Company 13F	3.1%	$78,940,665 2,006,116 shares	—	31 Mar 2026

How to read this table

Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.

Forms 3/4/5 flow

Insider trading overview

Net insider flow leans to selling over the last 12 months. Net value: -$43,400,101.

Buys

Insiders: 0

Sells

$43,400,101

Insiders: 9

Net

-$43,400,101

Shares: -1,004,705

Window

Last 12 months

4 rolling buckets

Buy value Sell value

Shares: 0 Shares: 1,004,705

Window (months)	Sell shares	Buy value	Sell value	Net value
0-3	123,752	$0	$10,752,423	-$10,752,423
3-6	313,551	$0	$14,666,242	-$14,666,242
6-9	311,250	$0	$10,432,090	-$10,432,090
9-12	256,152	$0	$7,549,347	-$7,549,347

Reporting owners

Insider holders from Forms 3/4/5

Showing 1-13 of 13 reporting-owner rows connected to ACM Research, Inc.. Open a relationship link for the CIK-to-CIK filing trail.

Rows

Largest Forms 3/4/5 holder

Shanghai Science & Technology Venture Capital (Group) Co., Ltd.

Net 12M change

-$43,400,102

Latest report

04 Jun 2026

Name	Relationship	Holdings Value	Past Year Net Change	Change %	Valuation	Report Date
Shanghai Science & Technology Venture Capital (Group) Co., Ltd.	Possible member of 10% group, 10%+ Owner	$120,382,639			Mixed	04 Oct 2024
David H. Wang	Chief Executive Officer, President and Director, Director, 10%+ Owner	$107,784,862	-$21,811,057	-17%	Mixed	03 Jun 2026
Xiao Xing	Director	$49,412,716			Filing P/S	04 Oct 2024
Haiping Dun	Director	$33,647,791	-$548,474	-1.6%	Mixed	19 May 2026
Yinan Xiang	Director	$25,215,740			Mixed	23 Aug 2021
Jian Wang	Chief Executive Officer and President of ACM Research (Shanghai), Inc., a subsidiary of the Issuer	$8,860,530	-$2,910,000	-25%	Filing P/S	18 Sep 2025
Sotheara Cheav	Senior Vice President, Manufacturing of ACM Research (Shanghai), Inc., a subsidiary of the Issuer.	$8,541,170	-$2,270,483	-21%	Filing P/S	04 Jun 2026
Tracy Liu	Director	$5,344,749	-$3,345,782	-38%	Filing P/S	10 Mar 2026
Chenming Hu	Director	$3,000,060			Filing P/S	17 Mar 2025
Lisa Feng	Chief Financial Officer of ACM Research (Shanghai), Inc., a subsidiary of the Issuer	$2,329,046	-$2,439,241	-51%	Filing P/S	05 Mar 2026
Mark McKechnie	Chief Financial Officer and Treasurer	$41,913	-$5,583,459	-99%	Filing P/S	12 Mar 2026
Fuping Chen	Vice President, Sales-China of ACM Research (Shanghai), Inc., a subsidiary of the Issuer	$0	-$3,981,156	-100%	Mixed	02 Dec 2025
Charles C. Pappis	Director	$0	-$510,450	-100%	Mixed	17 Apr 2026

Recent insider transactions for ACM Research, Inc.

Showing up to 300 recent insider transactions from the last 12 months.

Insider	Symbol	Class	Transaction	%	SEC-reported value	SEC-reported price	Shares	Shares owned	Date	Ownership
Sotheara Cheav	ACMR	Class A Common Stock	Sale	-5.12%	$449,085	$83.18	-5,399	100,002	05 Jun 2026	Direct
Sotheara Cheav	ACMR	Class A Common Stock	Options Exercise	5.4%			5,399	105,401	05 Jun 2026	Direct
Sotheara Cheav	ACMR	Stock Option	Options Exercise	-12.6%			-5,399	37,500	05 Jun 2026	Direct
Sotheara Cheav	ACMR	Class A Common Stock	Sale	-11.8%	$1,136,838	$85.15	-13,351	100,002	04 Jun 2026	Direct
Sotheara Cheav	ACMR	Class A Common Stock	Options Exercise	13.4%			13,351	113,353	04 Jun 2026	Direct
Sotheara Cheav	ACMR	Stock Option	Options Exercise	-23.7%			-13,351	42,899	04 Jun 2026	Direct
David H. Wang	ACMR	Class A Common Stock	Sale	-4.75%	$3,432,194	$85.80	-40,002	802,708	04 Jun 2026	Direct
David H. Wang	ACMR	Class A Common Stock	Options Exercise	4.98%			40,002	842,710	04 Jun 2026	Direct
David H. Wang	ACMR	Stock Option	Options Exercise	-12.9%			-40,002	270,000	04 Jun 2026	Direct
David H. Wang	ACMR	Class A Common Stock	Sale	-6.95%	$5,403,194	$90.05	-60,000	802,708	03 Jun 2026	Direct
David H. Wang	ACMR	Class A Common Stock	Options Exercise	7.47%			60,000	862,708	03 Jun 2026	Direct
David H. Wang	ACMR	Stock Option	Options Exercise	-16.2%			-60,000	310,002	03 Jun 2026	Direct
Haiping Dun	ACMR	Class A Common Stock	Sale	-100%	$331,111	$66.22	-5,000	0	19 May 2026	Direct
Haiping Dun	ACMR	Class A Common Stock	Options Exercise				5,000	5,000	19 May 2026	Direct
Haiping Dun	ACMR	Stock Option	Options Exercise	-9.09%			-5,000	50,000	19 May 2026	Direct
David H. Wang	ACMR	Restricted Stock Units	Award				6,208	6,208	13 May 2026	By Sophia Wang, daughter of David H. Wang
Charles C. Pappis	ACMR	Class A Common Stock	Sale	-100%	$260,000	$52.00	-5,000	0	17 Apr 2026	Direct
Charles C. Pappis	ACMR	Class A Common Stock	Options Exercise				5,000	5,000	17 Apr 2026	Direct
Charles C. Pappis	ACMR	Stock Option	Options Exercise	-100%			-5,000	0	17 Apr 2026	Direct
Mark McKechnie	ACMR	Class A Common Stock	Sale	-99.1%	$4,491,952	$45.58	-98,551	900	12 Mar 2026	Direct
Mark McKechnie	ACMR	Class A Common Stock	Options Exercise				98,551	60,900	12 Mar 2026	Direct
Mark McKechnie	ACMR	Stock Option	Options Exercise	-61.6%			-98,551	61,449	12 Mar 2026	Direct
David H. Wang	ACMR	Class A Common Stock	Sale	-5.86%	$2,278,923	$45.58	-50,000	802,708	12 Mar 2026	Direct
David H. Wang	ACMR	Class A Common Stock	Options Exercise	6.23%			50,000	852,708	12 Mar 2026	Direct
David H. Wang	ACMR	Stock Option	Options Exercise	-11.9%			-50,000	370,002	12 Mar 2026	Direct
David H. Wang	ACMR	Class A Common Stock	Sale	-6.95%	$2,875,482	$47.92	-60,000	802,708	11 Mar 2026	Direct
David H. Wang	ACMR	Class A Common Stock	Options Exercise	7.47%			60,000	862,708	11 Mar 2026	Direct
David H. Wang	ACMR	Stock Option	Options Exercise	-12.5%			-60,000	420,002	11 Mar 2026	Direct
Tracy Liu	ACMR	Class A Common Stock	Sale	-11.9%	$718,636	$47.91	-15,000	110,772	11 Mar 2026	Direct
Tracy Liu	ACMR	Class A Common Stock	Options Exercise	13.5%			15,000	125,772	11 Mar 2026	Direct
Tracy Liu	ACMR	Stock Option	Options Exercise	-100%			-15,000	0	11 Mar 2026	Direct
Tracy Liu	ACMR	Class A Common Stock	Sale	-28.9%	$2,132,146	$47.38	-45,000	110,772	10 Mar 2026	Direct
Tracy Liu	ACMR	Class A Common Stock	Options Exercise	40.6%			45,000	155,772	10 Mar 2026	Direct
Tracy Liu	ACMR	Stock Option	Options Exercise	-75%			-45,000	15,000	10 Mar 2026	Direct
Haiping Dun	ACMR	Class A Common Stock	Sale	-100%	$217,363	$43.47	-5,000	0	09 Mar 2026	Direct
Haiping Dun	ACMR	Class A Common Stock	Options Exercise				5,000	5,000	09 Mar 2026	Direct
Haiping Dun	ACMR	Stock Option	Options Exercise	-8.33%			-5,000	55,000	09 Mar 2026	Direct
Lisa Feng	ACMR	Class A Common Stock	Sale	-23.1%	$691,152	$46.08	-15,000	50,001	06 Mar 2026	Direct
Lisa Feng	ACMR	Class A Common Stock	Options Exercise	30%			15,000	65,001	06 Mar 2026	Direct
Lisa Feng	ACMR	Stock Option	Options Exercise	-100%			-15,000	0	06 Mar 2026	Direct
Charles C. Pappis	ACMR	Class A Common Stock	Sale	-100%	$250,450	$50.09	-5,000	0	05 Mar 2026	Direct
Charles C. Pappis	ACMR	Class A Common Stock	Options Exercise				5,000	5,000	05 Mar 2026	Direct
Charles C. Pappis	ACMR	Stock Option	Options Exercise	-50%			-5,000	5,000	05 Mar 2026	Direct
Lisa Feng	ACMR	Class A Common Stock	Sale	-23.1%	$750,138	$50.01	-15,000	50,001	05 Mar 2026	Direct
Lisa Feng	ACMR	Class A Common Stock	Options Exercise	30%			15,000	65,001	05 Mar 2026	Direct
Lisa Feng	ACMR	Stock Option	Options Exercise	-100%			-15,000	0	05 Mar 2026	Direct
David H. Wang	ACMR	Stock Option	Award	50%			545,400	1,636,197	04 Feb 2026	Direct
Mark McKechnie	ACMR	Class A Common Stock	Sale	-96.2%	$797,625	$35.45	-22,500	900	08 Dec 2025	Direct
Mark McKechnie	ACMR	Class A Common Stock	Options Exercise	2500%			22,500	23,400	08 Dec 2025	Direct
Mark McKechnie	ACMR	Stock Option	Options Exercise	-100%			-22,500	0	08 Dec 2025	Direct

^* marks a reported price that did not pass the local price check.