Who owns ACM Research (ACMR)?
105 holders named in SEC filings declare between 54.6% and 71.0% of ACM Research's shares outstanding, as of Sep 9, 2026. The largest are BlackRock (12.4%), Vanguard (9.0%) and Capital Group (4.3%); the five largest hold 31.3% together. Another 270 institutions hold small positions worth 2.8%. At least 26.2% of the shares appear in no ownership filing: investors who do not have to report, mostly individuals. From Mar 31, 2026 to Jun 30, 2026, institutions that filed both quarters bought 18.1% and sold 12.3% of the shares, a net purchase of 5.8%; 109 opened a position, 116 added, 89 reduced and 38 sold out. Biggest buyers: Capital Group (+3.0M shares) and Vanguard (+1.4M shares). Biggest sellers: WCM INVESTMENT MANAGEMENT, LLC (-943,223) and Longaeva Partners L.P. (-690,647). Directors and officers, from their latest Form 4: David H. Wang (2.4%) and Haiping Dun (1.2%). Over time, 363 managers declared ACM Research in their 13F for Q2 2026, against 41 for Q4 2019: together at most 67.4% of the shares outstanding, against 13.7%.
| Holder | Filing | Share of capital | As of | Holding since (13F) |
|---|---|---|---|---|
| BlackRock | 13F | 12.4% | Jun 30, 2026 | Q4 2019 or earlier |
| Vanguard | 13F | 9.0% | Jun 30, 2026 | Q4 2019 or earlier |
| Capital Group | 13F | 4.3% | Jun 30, 2026 | Q2 2026 |
| State Street | 13F | 3.1% | Jun 30, 2026 | Q4 2019 or earlier |
| David H. Wang | Form 4 | 2.4% | Sep 9, 2026 | — |
| Geode Capital | 13F | 2.1% | Jun 30, 2026 | Q4 2019 or earlier |
| Invesco | 13F | 1.7% | Jun 30, 2026 | Q2 2022 |
| Value Aligned Research Advisors, LLC | 13F | 1.5% | Jun 30, 2026 | Q1 2026 |
| WFM ASIA (BVI) Ltd | 13F | 1.4% | Jun 30, 2026 | Q2 2026 |
| Dimensional | 13F | 1.4% | Jun 30, 2026 | Q4 2025 |
| WCM INVESTMENT MANAGEMENT, LLC | 13F | 1.3% | Jun 30, 2026 | Q4 2025 |
| Haiping Dun | Form 4 | 1.2% | Aug 18, 2026 | — |
| Polunin Capital Partners Ltd | 13F | 1.1% | Jun 30, 2026 | Q1 2026 |
| Tekne Capital Management, LLC | 13F | 1.1% | Jun 30, 2026 | Q4 2025 |
| Morgan Stanley | 13F | 1.0% | Jun 30, 2026 | Q4 2019 or earlier |
| Fidelity (FMR) | 13F | 0.97% | Jun 30, 2026 | Q2 2022 |
| Fuller & Thaler Asset Management, Inc. | 13F | 0.92% | Jun 30, 2026 | Q2 2026 |
| GILDER GAGNON HOWE & CO LLC | 13F | 0.91% | Jun 30, 2026 | Q1 2024 |
| Citadel | 13F | 0.91% | Jun 30, 2026 | Q3 2022 |
| T. Rowe Price | 13F | 0.85% | Jun 30, 2026 | Q3 2020 |
| Northern Trust | 13F | 0.82% | Jun 30, 2026 | Q4 2019 or earlier |
| Janus Henderson | 13F | 0.80% | Jun 30, 2026 | Q4 2019 or earlier |
| UBS | 13F | 0.79% | Jun 30, 2026 | Q1 2020 |
| Charles Schwab | 13F | 0.76% | Jun 30, 2026 | Q3 2020 |
| Bank of America | 13F | 0.69% | Jun 30, 2026 | Q1 2020 |
ACM Research institutional ownership over time
| Quarter | 13F managers | Share of the company (upper bound) | Value declared | Held by stock pickers |
|---|---|---|---|---|
| Q4 2019 | 41 | 13.7% | $54.7M | 72.6% |
| Q4 2020 | 88 | 25.6% | $441.3M | 65.8% |
| Q4 2021 | 98 | 40.1% | $744.5M | 65.5% |
| Q4 2022 | 120 | 46.7% | $235.2M | 49.9% |
| Q4 2023 | 153 | 50.7% | $642.8M | 54.0% |
| Q4 2024 | 179 | 53.9% | $539.4M | 48.6% |
| Q4 2025 | 271 | 67.1% | $1.8B | 49.0% |
| Q2 2026 | 363 | 67.4% | $6.1B | 49.0% |
From SEC Form 13F, every quarter since the end of 2019, read like the current quarter: entities of a house summed, a value contradicting its share count set aside. The share of the company is an upper bound — two managers can declare the same shares — over the shares outstanding at that date.