Who owns ACM Research (ACMR)
Which tracked institutional funds hold ACMR, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See ACMR company fundamentals →
Ownership as of the 2026-Q2 13F filings (latest filed 2026-09-22). 13F is disclosed up to 45 days after quarter-end, so the most recent quarter fills in over the following weeks.
How the tape is positioned
The tracked-fund tape on ACMR is one-sided between 2026-Q1 and 2026-Q2: 202 added or opened and 46 trimmed or exited — on balance accumulating.
A prompt to read the filings, not a verdict. 13F is a quarter-end snapshot disclosed up to 45 days late; a fund adds or exits for mandate, benchmark, and timing reasons that have nothing to do with a view on the stock. This is a starting question, not a signal to trade.
Conviction spread
ACMR’s largest tracked holder by dollar value, BlackRock, Inc., sizes it at 0.0% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 0.0pp gap the other way — the median holder sizes ACMR more heavily than its largest holder by dollar value does.
Book-share is each fund’s reported value in ACMR divided by its whole reported 13F book, so it is comparable across funds of different sizes and is unaffected by stock splits. A higher share means a fund has committed more of its book to the name — a starting question about conviction, not a verdict or a signal to trade.
Institutional & insider positioning
Between 2026-Q1 and 2026-Q2, across 346 tracked filers holding ACMR, 226 increased or opened the position and 151 reduced or closed it; over the same quarter, open-market insider Form 4s were net sales.
This fuses two public signals for the same quarter — how tracked institutions changed their positions and whether insiders bought or sold in the open market. It describes what was filed; it is a starting question, not a verdict or a signal to trade.
New buyers & exits
Funds opening or closing a position in ACMR between the 2026-Q1 and 2026-Q2 13F filings, and the largest changes among funds holding it in both. New buyers and exits are counted on fund presence (split-invariant); adds and trims are measured on reported value.
New buyers 46
- Capital World Investors$304M
- FULLER & THALER ASSET MANAGEMENT, INC.$81M
- Capital International Investors$79M
- Jupiter Topco LLC$70M
- MY.Alpha Management HK Advisors Ltd$32M
- WELLINGTON MANAGEMENT GROUP LLP$22M
Full exits 37
- JANUS HENDERSON GROUP PLC$43M
- Polunin Capital Partners Ltd$32M
- Cederberg Capital Ltd$24M
- Oxbow Capital Management (HK) Ltd$23M
- LSV ASSET MANAGEMENT$21M
- Point72 Asset Management, L.P.$12M
Largest adds
- BlackRock, Inc.$876M
- VANGUARD PORTFOLIO MANAGEMENT LLC$338M
- VANGUARD CAPITAL MANAGEMENT LLC$223M
- STATE STREET CORP$199M
- GEODE CAPITAL MANAGEMENT, LLC$135M
- Invesco Ltd.$119M
Largest trims
- Longaeva Partners L.P.$26M
- SOUTHEASTERN ASSET MANAGEMENT INC/TN/$13M
- Engineers Gate Manager LP$1M
- Kerrisdale Advisers, LLC$865K
- XTX Topco Ltd$632K
- WELLS FARGO & COMPANY/MN$590K
Institutional holders
One row per tracked fund, most shares held first (every row is from one quarter; reported value breaks ties). “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding.
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| BlackRock, Inc. added | 8,660,842 | $1.1B | 19.6% | 2026-Q2 |
| VANGUARD PORTFOLIO MANAGEMENT LLC added | 3,349,436 | $425M | 7.6% | 2026-Q2 |
| VANGUARD CAPITAL MANAGEMENT LLC added | 2,462,745 | $312M | 5.6% | 2026-Q2 |
| Capital World Investors new | 2,398,036 | $304M | 5.4% | 2026-Q2 |
| STATE STREET CORP added | 2,188,254 | $278M | 5.0% | 2026-Q2 |
| GEODE CAPITAL MANAGEMENT, LLC added | 1,487,797 | $189M | 3.4% | 2026-Q2 |
| Invesco Ltd. added | 1,170,080 | $148M | 2.6% | 2026-Q2 |
| Value Aligned Research Advisors, LLC added | 1,053,949 | $134M | 2.4% | 2026-Q2 |
| DIMENSIONAL FUND ADVISORS LP added | 954,474 | $121M | 2.2% | 2026-Q2 |
| WCM INVESTMENT MANAGEMENT, LLC trimmed | 917,651 | $109M | 1.9% | 2026-Q2 |
| Tekne Capital Management, LLC added | 737,500 | $94M | 1.7% | 2026-Q2 |
| MORGAN STANLEY trimmed | 700,185 | $89M | 1.6% | 2026-Q2 |
| FMR LLC added | 672,184 | $85M | 1.5% | 2026-Q2 |
| FULLER & THALER ASSET MANAGEMENT, INC. trimmed | 639,448 | $81M | 1.4% | 2026-Q2 |
| GILDER GAGNON HOWE & CO LLC added | 637,058 | $81M | 1.4% | 2026-Q2 |
| CITADEL ADVISORS LLC added | 636,836 | $81M | 1.4% | 2026-Q2 |
| Capital International Investors new | 623,429 | $79M | 1.4% | 2026-Q2 |
| PRICE T ROWE ASSOCIATES INC /MD/ added | 591,573 | $75M | 1.3% | 2026-Q2 |
| NORTHERN TRUST CORP added | 569,126 | $72M | 1.3% | 2026-Q2 |
| Jupiter Topco LLC new | 553,768 | $70M | 1.3% | 2026-Q2 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC added | 526,760 | $67M | 1.2% | 2026-Q2 |
| BANK OF AMERICA CORP /DE/ added | 479,706 | $61M | 1.1% | 2026-Q2 |
| Tidal Investments LLC added | 470,937 | $60M | 1.1% | 2026-Q2 |
| GOLDMAN SACHS GROUP INC trimmed | 426,243 | $54M | 1.0% | 2026-Q2 |
| VANGUARD FIDUCIARY TRUST CO added | 404,100 | $51M | 0.9% | 2026-Q2 |
| UBS Group AG trimmed | 402,473 | $51M | 0.9% | 2026-Q2 |
| PRINCIPAL FINANCIAL GROUP INC added | 370,913 | $47M | 0.8% | 2026-Q2 |
| Raiffeisen Bank International AG trimmed | 360,000 | $43M | 0.8% | 2026-Q2 |
| WEXFORD CAPITAL LP trimmed | 355,400 | $45M | 0.8% | 2026-Q2 |
| Mitsubishi UFJ Trust & Banking Corp trimmed | 351,204 | $45M | 0.8% | 2026-Q2 |
| Bank of New York Mellon Corp added | 326,284 | $41M | 0.7% | 2026-Q2 |
| AQR CAPITAL MANAGEMENT LLC trimmed | 314,172 | $40M | 0.7% | 2026-Q2 |
| FIRST TRUST ADVISORS LP trimmed | 306,034 | $39M | 0.7% | 2026-Q2 |
| Penn Capital Management Company, LLC trimmed | 285,790 | $36M | 0.6% | 2026-Q2 |
| Qube Research & Technologies Ltd trimmed | 280,015 | $36M | 0.6% | 2026-Q2 |
| Oasis Management Co Ltd. added | 274,525 | $35M | 0.6% | 2026-Q2 |
| MACKENZIE FINANCIAL CORP added | 268,004 | $34M | 0.6% | 2026-Q2 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP added | 253,671 | $32M | 0.6% | 2026-Q2 |
| MY.Alpha Management HK Advisors Ltd added | 249,500 | $32M | 0.6% | 2026-Q2 |
| RENAISSANCE TECHNOLOGIES LLC added | 229,800 | $29M | 0.5% | 2026-Q2 |
| 12 West Capital Management LP added | 225,000 | $29M | 0.5% | 2026-Q2 |
| CONGRESS ASSET MANAGEMENT CO trimmed | 223,855 | $28M | 0.5% | 2026-Q2 |
| Russell Investments Group, Ltd. added | 221,775 | $28M | 0.5% | 2026-Q2 |
| JPMORGAN CHASE & CO trimmed | 214,853 | $26M | 0.5% | 2026-Q2 |
| TWO SIGMA INVESTMENTS, LP added | 212,544 | $27M | 0.5% | 2026-Q2 |
| CITIGROUP INC trimmed | 209,845 | $27M | 0.5% | 2026-Q2 |
| Public Sector Pension Investment Board added | 196,012 | $25M | 0.4% | 2026-Q2 |
| JACOBS LEVY EQUITY MANAGEMENT, INC trimmed | 191,966 | $24M | 0.4% | 2026-Q2 |
| NEW YORK STATE COMMON RETIREMENT FUND trimmed | 191,535 | $24M | 0.4% | 2026-Q2 |
| Steamboat Capital Partners, LLC trimmed | 182,773 | $23M | 0.4% | 2026-Q2 |
| Portolan Capital Management, LLC added | 177,432 | $23M | 0.4% | 2026-Q2 |
| WELLINGTON MANAGEMENT GROUP LLP new | 174,987 | $22M | 0.4% | 2026-Q2 |
| NOMURA ASSET MANAGEMENT INTERNATIONAL INC. added | 169,322 | $21M | 0.4% | 2026-Q2 |
| GROUP ONE TRADING LLC added | 157,056 | $20M | 0.4% | 2026-Q2 |
| Nuveen, LLC added | 148,494 | $19M | 0.3% | 2026-Q2 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC added | 146,414 | $19M | 0.3% | 2026-Q2 |
| FRANKLIN RESOURCES INC added | 145,385 | $18M | 0.3% | 2026-Q2 |
| MILLENNIUM MANAGEMENT LLC added | 140,501 | $18M | 0.3% | 2026-Q2 |
| SOUTHEASTERN ASSET MANAGEMENT INC/TN/ trimmed | 139,478 | $18M | 0.3% | 2026-Q2 |
| MATTHEWS INTERNATIONAL CAPITAL MANAGEMENT LLC trimmed | 132,396 | $17M | 0.3% | 2026-Q2 |
| RHUMBLINE ADVISERS trimmed | 128,979 | $16M | 0.3% | 2026-Q2 |
| Legal & General Group Plc trimmed | 125,619 | $16M | 0.3% | 2026-Q2 |
| BRIGHT VALLEY CAPITAL Ltd new | 118,000 | $15M | 0.3% | 2026-Q2 |
| DODGE & COX trimmed | 116,392 | $15M | 0.3% | 2026-Q2 |
| AMERIPRISE FINANCIAL INC trimmed | 115,178 | $15M | 0.3% | 2026-Q2 |
| Horiko Capital Management LLC added | 106,628 | $14M | 0.2% | 2026-Q2 |
| Swiss National Bank trimmed | 103,600 | $13M | 0.2% | 2026-Q2 |
| AMERICAN CENTURY COMPANIES INC trimmed | 101,200 | $13M | 0.2% | 2026-Q2 |
| RPg Family Wealth Advisory, LLC added | 98,166 | $12M | 0.2% | 2026-Q2 |
| LPL Financial LLC added | 93,288 | $12M | 0.2% | 2026-Q2 |
| DEUTSCHE BANK AG\ added | 90,500 | $11M | 0.2% | 2026-Q2 |
| BNP PARIBAS FINANCIAL MARKETS added | 86,340 | $11M | 0.2% | 2026-Q2 |
| STOREBRAND ASSET MANAGEMENT AS trimmed | 80,510 | $10M | 0.2% | 2026-Q2 |
| INTRINSIC EDGE CAPITAL MANAGEMENT LLC | 80,000 | $10M | 0.2% | 2026-Q2 |
| HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND added | 74,778 | $9M | 0.2% | 2026-Q2 |
| Kendall Capital Management trimmed | 72,820 | $9M | 0.2% | 2026-Q2 |
| Aperture Investors, LLC added | 70,569 | $9M | 0.2% | 2026-Q2 |
| LAZARD ASSET MANAGEMENT LLC added | 63,784 | $8M | 0.1% | 2026-Q2 |
| Atika Capital Management LLC new | 63,000 | $8M | 0.1% | 2026-Q2 |
| Inspire Investing, LLC added | 62,959 | $8M | 0.1% | 2026-Q2 |
| Kerrisdale Advisers, LLC trimmed | 62,570 | $8M | 0.1% | 2026-Q2 |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM trimmed | 59,702 | $8M | 0.1% | 2026-Q2 |
| WELLS FARGO & COMPANY/MN trimmed | 58,627 | $7M | 0.1% | 2026-Q2 |
| PRUDENTIAL FINANCIAL INC added | 58,505 | $7M | 0.1% | 2026-Q2 |
| Quantinno Capital Management LP added | 54,218 | $7M | 0.1% | 2026-Q2 |
| Quadrature Capital Ltd new | 48,891 | $6M | 0.1% | 2026-Q2 |
| SIMPLEX TRADING, LLC added | 44,316 | $6M | 0.1% | 2026-Q2 |
| NEUBERGER BERMAN GROUP LLC added | 44,245 | $5M | 0.1% | 2026-Q2 |
| Focus Partners Wealth added | 43,904 | $6M | 0.1% | 2026-Q2 |
| CenterBook Partners LP new | 41,438 | $5M | 0.1% | 2026-Q2 |
| BARCLAYS PLC trimmed | 40,321 | $5M | 0.1% | 2026-Q2 |
| SEI INVESTMENTS CO trimmed | 40,313 | $5M | 0.1% | 2026-Q2 |
| VANGUARD ASSET MANAGEMENT, Ltd added | 38,739 | $5M | 0.1% | 2026-Q2 |
| Kultura Capital Management LP new | 37,725 | $5M | 0.1% | 2026-Q2 |
| GUGGENHEIM CAPITAL LLC added | 37,530 | $5M | 0.1% | 2026-Q2 |
| STATE BOARD OF ADMINISTRATION OF FLORIDA RETIREMENT SYSTEM trimmed | 36,055 | $5M | 0.1% | 2026-Q2 |
| D. E. Shaw & Co., Inc. added | 33,500 | $4M | 0.1% | 2026-Q2 |
| Empirical Financial Services, LLC d.b.a. Empirical Wealth Management added | 33,153 | $4M | 0.1% | 2026-Q2 |
| Informed Momentum Co LLC trimmed | 31,875 | $4M | 0.1% | 2026-Q2 |
| MetLife Investment Management, LLC added | 31,382 | $4M | 0.1% | 2026-Q2 |
Ownership over time
Tracked institutional holder count and total shares held by filing quarter (independent scales). The curated-era tail and any mid-ingest latest quarter are handled honestly — a partial quarter is not drawn as a collapse.
Reading this table
Funds hold the same stock for different reasons — an index fund “holds” almost everything, an active manager sizes a name to a mandate and a benchmark, and each fund entered at its own price and time. Because 13F is filed up to 45 days after quarter-end, every row is a backward-looking snapshot; a manager may have traded since. Share-class siblings (a company’s A and C shares) are rolled up to one line so a dual-class name is never double-counted. Compare like-for-like. A large holder is not an endorsement, and a fund exiting is not a warning — this is a starting question, not a verdict.
About 13F filings
A Form 13F is a quarterly disclosure that institutional investment managers with over $100 million in US-listed equities must file with the SEC. In plain English: it is a snapshot of the long stock positions a fund held at the end of a quarter. It covers long US-listed equities only — not short positions, options, cash, or private holdings — and the funds shown are the large sample we track, not the complete 13F universe.