Comparable stake leader
BlackRock, Inc.
SEC ownership of ACM Research, Inc.
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001680062.
Disclosed value leader
BlackRock, Inc.
Comparable rows
50/50
Latest evidence
31 Mar 2026
- Symbol
- ACMR on Nasdaq
- Ownership evidence mix
- 13F, 13D/G, and 3/4/5
- Largest current holder
- BlackRock, Inc.
- Latest large-stake holder
- BlackRock, Inc.
- Latest evidence date
- 31 Mar 2026
- CIK
- 0001680062
- Location
- Fremont, CA
Ownership snapshot
2 facts
Issuer identity
2 facts
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
BlackRock, Inc.
Comparable rows
50/50
Latest evidence
31 Mar 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.
Comparable ownership
Top 5
BlackRock, Inc.
13%
Yiheng Capital Management, L.P.
1.2%
Jian Wang
0.42%
Tracy Liu
0.18%
Lisa Feng
0.08%
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
|
13%
from 13D/G
|
$314,203,729
7,984,847 shares
|
— | 31 Mar 2026 |
| Yiheng Capital Management, L.P. |
13D/G
Yiheng Capital Partners, L.P.
|
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
|
0.42%
|
$8,860,530
253,158 shares
|
-$2,910,000 | 18 Sep 2025 |
| Tracy Liu |
3/4/5
Director
|
0.18%
|
$5,344,749
110,772 shares
|
-$3,795,782 | 10 Mar 2026 |
| Lisa Feng |
3/4/5
Chief Financial Officer of ACM Research (Shanghai), Inc., a subsidiary of the Issuer
|
0.08%
|
$2,329,046
50,001 shares
|
-$3,249,241 | 05 Mar 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC |
13F
Company
|
3.8%
|
$89,101,661
2,264,337 shares
|
— | 31 Mar 2026 |
| VANGUARD PORTFOLIO MANAGEMENT LLC |
13F
Company
|
3.7%
|
$86,720,750
2,203,831 shares
|
— | 31 Mar 2026 |
| STATE STREET CORP |
13F
Company
|
3.3%
|
$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: -$34,238,789.
Buys
$0
Insiders: 0
Sells
$34,238,789
Insiders: 9
Net
-$34,238,789
Shares: -930,953
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 0
Shares: 930,953
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 0 | 318,551 | $0 | $14,997,353 | -$14,997,353 |
| 3-6 | 0 | 281,250 | $0 | $9,434,140 | -$9,434,140 |
| 6-9 | 0 | 215,000 | $0 | $6,352,737 | -$6,352,737 |
| 9-12 | 0 | 116,152 | $0 | $3,454,560 | -$3,454,560 |
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
13
Largest current holder
Shanghai Science & Technology Venture Capital (Group) Co., Ltd.
Net 12M change
-$34,238,790
Latest report
19 May 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| 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 | ||
| 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 | ||
| Mark McKechnie | ACMR | Class A Common Stock | Sale | -90.7% | $293,882 | $33.59 | -8,750 | 900 | 04 Dec 2025 | Direct |
| Mark McKechnie | ACMR | Class A Common Stock | Options Exercise | 972.2% | 8,750 | 9,650 | 04 Dec 2025 | Direct | ||
| Mark McKechnie | ACMR | Stock Option | Options Exercise | -100% | -8,750 | 0 | 04 Dec 2025 | Direct | ||
| David H. Wang | ACMR | Class A Common Stock | Sale | -6.95% | $2,047,365 | $34.12 | -60,000 | 802,708 | 04 Dec 2025 | Direct |
| David H. Wang | ACMR | Class A Common Stock | Options Exercise | 7.47% | 60,000 | 862,708 | 04 Dec 2025 | Direct | ||
| David H. Wang | ACMR | Stock Option | Options Exercise | -11.1% | -60,000 | 480,002 | 04 Dec 2025 | Direct | ||
| David H. Wang | ACMR | Class A Common Stock | Sale | -8.02% | $2,314,112 | $33.06 | -70,000 | 802,708 | 03 Dec 2025 | Direct |
| David H. Wang | ACMR | Class A Common Stock | Options Exercise | 8.72% | 70,000 | 872,708 | 03 Dec 2025 | Direct | ||
| David H. Wang | ACMR | Stock Option | Options Exercise | -11.5% | -70,000 | 540,002 | 03 Dec 2025 | Direct | ||
| Fuping Chen | ACMR | Class A Common Stock | Sale | -100% | $661,156 | $33.06 | -20,000 | 0 | 03 Dec 2025 | Direct |
| Fuping Chen | ACMR | Class A Common Stock | Options Exercise | 20,000 | 20,000 | 03 Dec 2025 | Direct | |||
| Fuping Chen | ACMR | Stock Option | Options Exercise | -48.6% | -20,000 | 21,165 | 03 Dec 2025 | Direct | ||
| Fuping Chen | ACMR | Class A Common Stock | Sale | -100% | $3,320,000 | $33.20 | -100,000 | 0 | 02 Dec 2025 | Direct |
* marks a reported price that did not pass the local price check.