Who owns Adicet Bio (ACET)
Which tracked institutional funds hold ACET, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See ACET 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 ACET is one-sided between 2026-Q1 and 2026-Q2: 17 added or opened and 3 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
ACET’s largest tracked holder by dollar value, RA CAPITAL MANAGEMENT, L.P., sizes it at 0.1% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 0.1pp conviction gap — its largest holder concentrates the name more heavily than the typical one.
Book-share is each fund’s reported value in ACET 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 54 tracked filers holding ACET, 30 increased or opened the position and 16 reduced or closed it; over the same quarter, open-market insider Form 4s were net purchases.
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 ACET 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 3
- Schonfeld Strategic Advisors LLC$2M
- BRIDGEWAY CAPITAL MANAGEMENT, LLC$743K
- MARSHALL WACE, LLP$687K
Full exits 3
- Woodline Partners LP$2M
- Prosight Management, LP$2M
- ACADIAN ASSET MANAGEMENT LLC$802K
Largest adds
- FRANKLIN RESOURCES INC$1M
- CITADEL ADVISORS LLC$1M
- RENAISSANCE TECHNOLOGIES LLC$714K
- VANGUARD CAPITAL MANAGEMENT LLC$674K
- Stonepine Capital Management, LLC$610K
- TWO SIGMA INVESTMENTS, LP$543K
Institutional holders
One row per tracked fund, largest reported value first. “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding. Rows marked stale are from an earlier filing than the security’s latest quarter — that fund is absent from the newest snapshot (position exited, or reported under a different name).
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| RA CAPITAL MANAGEMENT, L.P. trimmed | 932,624 | $8M | 12.4% | 2026-Q2 |
| ORBIMED ADVISORS LLC trimmed | 844,787 | $7M | 11.3% | 2026-Q2 |
| FRANKLIN RESOURCES INC | 626,571 | $5M | 8.3% | 2026-Q2 |
| CITADEL ADVISORS LLC added | 432,738 | $4M | 5.8% | 2026-Q2 |
| VANGUARD CAPITAL MANAGEMENT LLC added | 343,228 | $3M | 4.6% | 2026-Q2 |
| ADAGE CAPITAL PARTNERS GP, L.L.C. | 274,375 | $2M | 3.7% | 2026-Q2 |
| RENAISSANCE TECHNOLOGIES LLC added | 265,945 | $2M | 3.5% | 2026-Q2 |
| Stonepine Capital Management, LLC added | 245,518 | $2M | 3.3% | 2026-Q2 |
| Alyeska Investment Group, L.P. | 203,799 | $2M | 2.7% | 2026-Q2 |
| Schonfeld Strategic Advisors LLC trimmed | 195,514 | $2M | 2.6% | 2026-Q2 |
| Carlyle Group Inc. | 184,295 | $2M | 2.5% | 2026-Q2 |
| NEXTBio Capital Management LP | 157,827 | $1M | 2.1% | 2026-Q2 |
| TWO SIGMA INVESTMENTS, LP added | 96,839 | $837K | 1.3% | 2026-Q2 |
| GEODE CAPITAL MANAGEMENT, LLC trimmed | 95,634 | $827K | 1.3% | 2026-Q2 |
| DAFNA Capital Management LLC | 93,812 | $811K | 1.3% | 2026-Q2 |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC added | 85,959 | $743K | 1.1% | 2026-Q2 |
| MARSHALL WACE, LLP added | 79,488 | $687K | 1.1% | 2026-Q2 |
| Trexquant Investment LP added | 78,002 | $674K | 1.0% | 2026-Q2 |
| JANE STREET GROUP, LLC added | 70,561 | $610K | 0.9% | 2026-Q2 |
| Burkehill Global Management, LP | 62,500 | $540K | 0.8% | 2026-Q2 |
| BlackRock, Inc. added | 62,126 | $537K | 0.8% | 2026-Q2 |
| REGENERON PHARMACEUTICALS, INC. | 60,511 | $523K | 0.8% | 2026-Q2 |
| Rangeley Capital, LLC trimmed | 50,892 | $440K | 0.7% | 2026-Q2 |
| VANGUARD FIDUCIARY TRUST CO added | 50,670 | $438K | 0.7% | 2026-Q2 |
| RBF Capital, LLC | 38,582 | $333K | 0.5% | 2026-Q2 |
| STATE STREET CORP | 36,222 | $313K | 0.5% | 2026-Q2 |
| Quadrature Capital Ltd new | 36,193 | $313K | 0.5% | 2026-Q2 |
| DIMENSIONAL FUND ADVISORS LP added | 31,603 | $273K | 0.4% | 2026-Q2 |
| UBS Group AG trimmed | 29,817 | $258K | 0.4% | 2026-Q2 |
| Verdad Advisers, LP new | 25,200 | $218K | 0.3% | 2026-Q2 |
| XTX Topco Ltd added | 24,284 | $210K | 0.3% | 2026-Q2 |
| JOHNSON & JOHNSON | 22,779 | $197K | 0.3% | 2026-Q2 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP trimmed | 20,650 | $178K | 0.3% | 2026-Q2 |
| PRELUDE CAPITAL MANAGEMENT, LLC trimmed | 18,550 | $160K | 0.2% | 2026-Q2 |
| NORTHERN TRUST CORP trimmed | 18,436 | $159K | 0.2% | 2026-Q2 |
| OCCUDO QUANTITATIVE STRATEGIES LP added | 16,636 | $144K | 0.2% | 2026-Q2 |
| Squarepoint Ops LLC trimmed | 15,254 | $132K | 0.2% | 2026-Q2 |
| Vontobel Holding Ltd. trimmed | 13,776 | $119K | 0.2% | 2026-Q2 |
| AXQ CAPITAL, LP new | 10,991 | $95K | 0.1% | 2026-Q2 |
| Jump Financial, LLC new | 10,942 | $95K | 0.1% | 2026-Q2 |
| Arax Advisory Partners new | 6,000 | $52K | 0.1% | 2026-Q2 |
| Vanguard Global Advisers, LLC | 5,221 | $45K | 0.1% | 2026-Q2 |
| SIMPLEX TRADING, LLC added | 4,814 | $42K | 0.1% | 2026-Q2 |
| MORGAN STANLEY trimmed | 2,291 | $20K | 0.0% | 2026-Q2 |
| ROYAL BANK OF CANADA added | 1,701 | $15K | 0.0% | 2026-Q2 |
| Tower Research Capital LLC (TRC) trimmed | 277 | $2K | 0.0% | 2026-Q2 |
| JPMORGAN CHASE & CO added | 196 | $2K | 0.0% | 2026-Q2 |
| BNP PARIBAS FINANCIAL MARKETS | 50 | $432 | 0.0% | 2026-Q2 |
| Caitong International Asset Management Co., Ltd added | 47 | $406 | 0.0% | 2026-Q2 |
| SBI Securities Co., Ltd. added | 24 | $207 | 0.0% | 2026-Q2 |
| NATIONAL BANK OF CANADA /FI/ | 17 | $146 | 0.0% | 2026-Q2 |
| FMR LLC trimmed | 6 | $52 | 0.0% | 2026-Q2 |
| TD Waterhouse Canada Inc. new | 3 | $26 | 0.0% | 2026-Q2 |
| DANSKE BANK A/S | 1 | $9 | 0.0% | 2026-Q2 |
| Woodline Partners LP trimmed | 313,124 | $2M | 3.3% | 2026-Q1 stale (1 quarter behind) |
| Prosight Management, LP | 250,244 | $2M | 2.6% | 2026-Q1 stale (1 quarter behind) |
| ACADIAN ASSET MANAGEMENT LLC trimmed | 118,138 | $802K | 1.2% | 2026-Q1 stale (1 quarter behind) |
| ADAR1 Capital Management, LLC trimmed | 53,827 | $367K | 0.6% | 2026-Q1 stale (1 quarter behind) |
| BARCLAYS PLC | 25,000 | $170K | 0.3% | 2026-Q1 stale (1 quarter behind) |
| FNY Investment Advisers, LLC trimmed | 3,200 | $21K | 0.0% | 2026-Q1 stale (1 quarter behind) |
| Avion Wealth new | 246 | $1K | 0.0% | 2026-Q1 stale (1 quarter behind) |
| VANGUARD GROUP INC trimmed | 291,277 | $2M | 3.8% | 2025-Q4 stale (2 quarters behind) |
| GOLDMAN SACHS GROUP INC trimmed | 234,510 | $2M | 3.0% | 2025-Q4 stale (2 quarters behind) |
| TWO SIGMA ADVISERS, LP trimmed | 111,336 | $937K | 1.4% | 2025-Q4 stale (2 quarters behind) |
| LUMINUS MANAGEMENT LLC trimmed | 59,558 | $501K | 0.8% | 2025-Q4 stale (2 quarters behind) |
| Maven Securities LTD new | 31,250 | $263K | 0.4% | 2025-Q4 stale (2 quarters behind) |
| GSA CAPITAL PARTNERS LLP added | 17,763 | $150K | 0.2% | 2025-Q4 stale (2 quarters behind) |
| TANG CAPITAL MANAGEMENT LLC trimmed | 6,158 | $52K | 0.1% | 2025-Q4 stale (2 quarters behind) |
| BANK OF AMERICA CORP /DE/ trimmed | 1,288 | $11K | 0.0% | 2025-Q4 stale (2 quarters behind) |
| HOLLENCREST CAPITAL MANAGEMENT trimmed | 250 | $2K | 0.0% | 2025-Q4 stale (2 quarters behind) |
| NORGES BANK | 429,550 | $619K | 1.0% | 2025-Q3 stale (3 quarters behind) |
| MILLENNIUM MANAGEMENT LLC trimmed | 565,953 | $459K | 0.7% | 2025-Q3 stale (3 quarters behind) |
| WEALTHEDGE INVESTMENT ADVISORS, LLC trimmed | 300,054 | $243K | 0.4% | 2025-Q3 stale (3 quarters behind) |
| Virtu Financial LLC added | 79,916 | $65K | 0.1% | 2025-Q3 stale (3 quarters behind) |
| BLUEFIN CAPITAL MANAGEMENT, LLC new | 66,854 | $54K | 0.1% | 2025-Q3 stale (3 quarters behind) |
| Abacus Planning Group, Inc. | 36,764 | $30K | 0.0% | 2025-Q3 stale (3 quarters behind) |
| TWO SIGMA SECURITIES, LLC added | 25,274 | $20K | 0.0% | 2025-Q3 stale (3 quarters behind) |
| Qube Research & Technologies Ltd added | 20,257 | $16K | 0.0% | 2025-Q3 stale (3 quarters behind) |
| HRT FINANCIAL LP new | 18,627 | $15K | 0.0% | 2025-Q3 stale (3 quarters behind) |
| Mariner, LLC new | 14,850 | $12K | 0.0% | 2025-Q3 stale (3 quarters behind) |
| RAYMOND JAMES FINANCIAL INC added | 13,265 | $11K | 0.0% | 2025-Q3 stale (3 quarters behind) |
| TOTH FINANCIAL ADVISORY CORP | 1,600 | $1K | 0.0% | 2025-Q3 stale (3 quarters behind) |
| Advisory Services Network, LLC new | 316 | $256 | 0.0% | 2025-Q3 stale (3 quarters behind) |
| CITIGROUP INC trimmed | 166 | $134 | 0.0% | 2025-Q3 stale (3 quarters behind) |
| OSAIC HOLDINGS, INC. new | 10 | $7 | 0.0% | 2025-Q3 stale (3 quarters behind) |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC | 30,000 | $18K | 0.0% | 2025-Q2 stale (4 quarters behind) |
| D. E. Shaw & Co., Inc. trimmed | 22,199 | $14K | 0.0% | 2025-Q2 stale (4 quarters behind) |
| LANDSCAPE CAPITAL MANAGEMENT, L.L.C. new | 17,846 | $11K | 0.0% | 2025-Q2 stale (4 quarters behind) |
| Riggs Asset Managment Co. Inc. new | 1,122 | $685 | 0.0% | 2025-Q2 stale (4 quarters behind) |
| CONCOURSE FINANCIAL GROUP SECURITIES, INC. | 0 | — | 0.0% | 2025-Q2 stale (4 quarters behind) |
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.