ACM Research, Inc. (ACMR) Ownership
ACMR ownership summary
as of October 18, 2026- Institutions
- 77.9% of shares outstanding
- Insiders
- 3.86% of shares outstanding
- Shares outstanding
- 64.7M
- Float
- 61.5M shares available to trade
- Short interest
- 7.49% 4.1M shares short
- Days to cover
- 3.68 short interest down 2.0% vs prior month
- Institutions 77.88%
- Insiders 3.86%
- Other investors 18.25%
ACMR top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | BlackRock Inc | 12.43% | 8.7M | $459.9M | +675,995 (+8.5%) | June 30, 2026 |
| 2 | Vanguard Portfolio Management, LLC | 4.81% | 3.3M | $177.9M | +1.1M (+52.0%) | June 30, 2026 |
| 3 | Vanguard Capital Management, LLC | 3.54% | 2.5M | $130.8M | +198,408 (+8.8%) | June 30, 2026 |
| 4 | Capital World Investors | 3.44% | 2.4M | $127.3M | +2.4M (0.0%) | June 30, 2026 |
| 5 | State Street Corp | 3.14% | 2.2M | $116.2M | +182,138 (+9.1%) | June 30, 2026 |
| 6 | Geode Capital Management, LLC | 2.14% | 1.5M | $79.0M | +116,570 (+8.5%) | June 30, 2026 |
| 7 | Amvescap Plc. | 1.68% | 1.2M | $62.1M | +382,979 (+48.7%) | June 30, 2026 |
| 8 | HHG PLC | 1.56% | 1.1M | $57.6M | +2,652 (+0.2%) | March 31, 2026 |
| 9 | Value Aligned Research Advisors LLC | 1.51% | 1.1M | $56.0M | +98,022 (+10.3%) | June 30, 2026 |
| 10 | Ward Ferry Management (Bvi) Limited | 1.39% | 969K | $51.5M | +969,200 (0.0%) | June 30, 2026 |
| 11 | Dimensional Fund Advisors, Inc. | 1.37% | 954K | $50.7M | +235,451 (+32.7%) | June 30, 2026 |
| 12 | WCM Investment Management | 1.32% | 918K | $48.7M | −943,223 (−50.7%) | June 30, 2026 |
| 13 | Polunin Capital Partners Ltd | 1.07% | 748K | $39.7M | −14,820 (−1.9%) | June 30, 2026 |
| 14 | Tekne Capital Management, LLC | 1.06% | 738K | $39.2M | +22,500 (+3.1%) | June 30, 2026 |
| 15 | Morgan Stanley - Brokerage Accounts | 1.01% | 700K | $37.2M | −492,520 (−41.3%) | June 30, 2026 |
| 16 | FMR Inc | 0.97% | 672K | $35.7M | +42,940 (+6.8%) | June 30, 2026 |
| 17 | Fuller & Thaler Asset Management Inc | 0.92% | 639K | $34.0M | +639,448 (0.0%) | June 30, 2026 |
| 18 | Gilder Gagnon Howe & CO LLC | 0.91% | 637K | $33.8M | +565,813 (+794.2%) | June 30, 2026 |
| 19 | Citadel Advisors Llc | 0.91% | 637K | $33.8M | +433,458 (+213.1%) | June 30, 2026 |
| 20 | Capital Research & Mgmt Co - Division 3 | 0.90% | 623K | $33.1M | +623,429 (0.0%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 17 holders added 8.7M shares and 3 cut 1.5M.
ACMR top mutual fund and ETF holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | iShares Core S&P Small-Cap ETF | 5.03% | 3.5M | $185.9M | +771 (+0.0%) | September 30, 2026 |
| 2 | American Funds SMALLCAP World A | 4.23% | 2.9M | $156.4M | +18,104 (+0.6%) | September 30, 2026 |
| 3 | Vanguard MStar Total Stk Mkt Idx Invest | 2.52% | 1.8M | $93.1M | −2,006 (−0.1%) | August 31, 2026 |
| 4 | iShares Russell 2000 ETF | 2.11% | 1.5M | $78.1M | −16,960 (−1.1%) | September 30, 2026 |
| 5 | Vanguard Information Technology ETF | 1.81% | 1.3M | $67.1M | +2,905 (+0.2%) | September 30, 2026 |
| 6 | Invesco Semiconductors ETF | 1.26% | 880K | $46.7M | — | September 30, 2026 |
| 7 | Vanguard Small Cap Index | 0.94% | 655K | $34.8M | +21,699 (+3.4%) | September 30, 2026 |
| 8 | Fidelity Small Cap Index | 0.85% | 590K | $31.3M | +4,992 (+0.9%) | July 31, 2026 |
| 9 | iShares S&P Small-Cap 600 Growth ETF | 0.78% | 546K | $29.0M | — | September 30, 2026 |
| 10 | iShares Russell 2000 Growth ETF | 0.77% | 533K | $28.3M | −675 (−0.1%) | September 30, 2026 |
| 11 | State Street SPDR Port S&P 600 Sm CpETF | 0.76% | 531K | $28.2M | — | September 30, 2026 |
| 12 | YieldMax Semiconductor Port Opt Inc ETF | 0.76% | 526K | $27.9M | +2,118 (+0.4%) | September 30, 2026 |
| 13 | Janus Henderson Hrzn GlbTechLdrs A2USD | 0.64% | 444K | $23.6M | +96,090 (+27.6%) | August 31, 2026 |
| 14 | Fidelity Enhanced Small Cap Core ETF | 0.62% | 434K | $23.0M | — | September 30, 2026 |
| 15 | Vanguard MStar Small Cap Growth Indx Inv | 0.52% | 365K | $19.4M | +1,887 (+0.5%) | September 30, 2026 |
| 16 | State Street® SPDR® S&P 600™ Sm Cp GrETF | 0.49% | 339K | $18.0M | — | September 30, 2026 |
| 17 | Vanguard Russell 2000 ETF | 0.48% | 331K | $17.6M | +21,148 (+6.8%) | September 30, 2026 |
| 18 | Invesco S&P SmallCap Momentum ETF | 0.46% | 318K | $16.9M | — | September 30, 2026 |
| 19 | Vanguard Tax-Managed Small Cap Adm | 0.45% | 313K | $16.6M | — | September 30, 2026 |
| 20 | Schwab US Small-Cap ETF™ | 0.44% | 310K | $16.4M | +207 (+0.1%) | September 30, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
ACMR insider transactions
latest 20| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2026-04-17 | Charles C Pappis | Sell | $52.00 | 5,000 | $260,000 |
| 2026-03-11 | Tracy Liu | Sell | $47.91 | 15,000 | $718,650 |
| 2026-03-10 | Tracy Liu | Sell | $47.38 | 45,000 | $2.1M |
| 2025-12-04 | David H Wang | Sell | $34.12 | 60,000 | $2.0M |
| 2025-12-03 | David H Wang | Sell | $33.06 | 70,000 | $2.3M |
| 2025-12-03 | Fuping Chen | Sell | $33.06 | 20,000 | $661,200 |
| 2025-12-02 | Fuping Chen | Sell | $33.20 | 100,000 | $3.3M |
| 2025-11-13 | Lisa Feng | Sell | $33.77 | 15,000 | $506,550 |
| 2025-09-18 | Jian Wang | Sell | $35.00 | 30,000 | $1.1M |
| 2025-09-18 | Sotheara Cheav | Sell | $35.00 | 10,000 | $350,000 |
| 2025-09-17 | Tracy Liu | Sell | $33.00 | 15,000 | $495,000 |
| 2025-09-04 | David H Wang | Sell | $26.44 | 60,000 | $1.6M |
| 2025-09-03 | David H Wang | Sell | $26.76 | 70,000 | $1.9M |
| 2025-08-25 | Jian Wang | Sell | $32.00 | 30,000 | $960,000 |
| 2025-08-22 | Jian Wang | Sell | $30.00 | 30,000 | $900,000 |
| 2025-08-22 | Sotheara Cheav | Sell | $30.00 | 11,152 | $334,560 |
| 2025-07-15 | Tracy Liu | Sell | $30.00 | 15,000 | $450,000 |
| 2025-07-07 | Lisa Feng | Sell | $28.00 | 15,000 | $420,000 |
| 2025-06-24 | Lisa Feng | Sell | $26.00 | 15,000 | $390,000 |
| 2025-05-22 | David H Wang | Sell | $22.63 | 60,000 | $1.4M |
Reported trades by company officers, directors and other filers (including disclosures by members of Congress where EODHD lists them). "—" where the filing gives no share count.
ACMR shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns ACMR
Institutional investors own 77.9% of ACM Research's shares and insiders 3.86%. The largest holder is BlackRock Inc with 12.43% of the shares (8.7M), as of June 30, 2026. Among the top 20 institutions, 17 added shares and 3 reduced their stake in the latest filings. Short interest is 7.49% of the float, or 3.68 days of average trading volume. The share count rose 611.3% since 2015.
Related: ACMR analyst forecast, ACMR key metrics. See the ACMR stock overview for the latest quote and news.
ACMR ownership FAQ
Who owns the most ACM Research stock?
The largest shareholders of ACM Research are BlackRock Inc (12.43%), Vanguard Portfolio Management, LLC (4.81%), Vanguard Capital Management, LLC (3.54%), Capital World Investors (3.44%), State Street Corp (3.14%).
What percentage of ACM Research is owned by institutions?
Institutions hold 77.9% of ACM Research's shares outstanding; insiders hold 3.86%.
Which funds own ACM Research?
The largest fund holders of ACM Research are iShares Core S&P Small-Cap ETF (5.03%), American Funds SMALLCAP World A (4.23%), Vanguard MStar Total Stk Mkt Idx Invest (2.52%), iShares Russell 2000 ETF (2.11%), Vanguard Information Technology ETF (1.81%).
What is ACM Research's short interest?
4.1M shares of ACM Research were sold short, 7.49% of the float; at the average daily volume it would take 3.68 days to cover.
Are insiders buying or selling ACM Research?
Of the latest 20 reported insider transactions in ACM Research (since May 22, 2025), 0 were purchases and 20 were sales.
How many shares of ACM Research are outstanding?
ACM Research has 64.7M shares outstanding, of which 61.5M are in the public float.