Who owns ACET (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-Q1 13F filings. 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 2025-Q4 and 2026-Q1: 2 added or opened and 17 trimmed or exited — on balance reducing.
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 2025-Q4 and 2026-Q1, across 48 tracked filers holding ACET, 23 increased or opened the position and 20 reduced or closed it; over the same quarter, there were no open-market insider Form 4s.
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 2025-Q4 and 2026-Q1 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 1
- VANGUARD CAPITAL MANAGEMENT LLC$2M
Full exits 4
- VANGUARD GROUP INC$2M
- GOLDMAN SACHS GROUP INC$2M
- TWO SIGMA ADVISERS, LP$937K
- LUMINUS MANAGEMENT LLC$501K
Largest adds
- CITADEL ADVISORS LLC$2M
Largest trims
- Woodline Partners LP$3M
- ORBIMED ADVISORS LLC$2M
- FRANKLIN RESOURCES INC$1M
- TWO SIGMA INVESTMENTS, LP$926K
- ACADIAN ASSET MANAGEMENT LLC$723K
- ADAR1 Capital Management, LLC$717K
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. added | 1,182,624 | $8M | 14.4% | 2026-Q1 |
| ORBIMED ADVISORS LLC | 1,027,944 | $7M | 12.5% | 2026-Q1 |
| FRANKLIN RESOURCES INC | 626,571 | $4M | 7.6% | 2026-Q1 |
| CITADEL ADVISORS LLC added | 381,823 | $3M | 4.7% | 2026-Q1 |
| VANGUARD CAPITAL MANAGEMENT LLC new | 336,524 | $2M | 4.1% | 2026-Q1 |
| Woodline Partners LP trimmed | 313,124 | $2M | 3.8% | 2026-Q1 |
| ADAGE CAPITAL PARTNERS GP, L.L.C. | 274,375 | $2M | 3.3% | 2026-Q1 |
| Prosight Management, LP | 250,244 | $2M | 3.1% | 2026-Q1 |
| RENAISSANCE TECHNOLOGIES LLC trimmed | 232,591 | $2M | 2.8% | 2026-Q1 |
| Stonepine Capital Management, LLC added | 221,955 | $2M | 2.7% | 2026-Q1 |
| Alyeska Investment Group, L.P. | 203,799 | $1M | 2.5% | 2026-Q1 |
| Carlyle Group Inc. | 184,295 | $1M | 2.2% | 2026-Q1 |
| NEXTBio Capital Management LP | 157,827 | $1M | 1.9% | 2026-Q1 |
| ACADIAN ASSET MANAGEMENT LLC trimmed | 118,138 | $802K | 1.4% | 2026-Q1 |
| GEODE CAPITAL MANAGEMENT, LLC added | 101,135 | $689K | 1.2% | 2026-Q1 |
| DAFNA Capital Management LLC | 93,812 | $639K | 1.1% | 2026-Q1 |
| Burkehill Global Management, LP | 62,500 | $426K | 0.8% | 2026-Q1 |
| REGENERON PHARMACEUTICALS, INC. | 60,511 | $412K | 0.7% | 2026-Q1 |
| Rangeley Capital, LLC added | 56,000 | $381K | 0.7% | 2026-Q1 |
| ADAR1 Capital Management, LLC trimmed | 53,827 | $367K | 0.7% | 2026-Q1 |
| VANGUARD FIDUCIARY TRUST CO new | 50,334 | $343K | 0.6% | 2026-Q1 |
| Trexquant Investment LP trimmed | 43,666 | $297K | 0.5% | 2026-Q1 |
| TWO SIGMA INVESTMENTS, LP trimmed | 43,106 | $294K | 0.5% | 2026-Q1 |
| RBF Capital, LLC | 38,582 | $263K | 0.5% | 2026-Q1 |
| UBS Group AG added | 38,368 | $261K | 0.5% | 2026-Q1 |
| JANE STREET GROUP, LLC trimmed | 37,084 | $253K | 0.5% | 2026-Q1 |
| BlackRock, Inc. | 36,585 | $249K | 0.4% | 2026-Q1 |
| STATE STREET CORP added | 36,222 | $247K | 0.4% | 2026-Q1 |
| BARCLAYS PLC | 25,000 | $170K | 0.3% | 2026-Q1 |
| JOHNSON & JOHNSON | 22,779 | $155K | 0.3% | 2026-Q1 |
| NORTHERN TRUST CORP added | 19,200 | $131K | 0.2% | 2026-Q1 |
| XTX Topco Ltd added | 19,126 | $130K | 0.2% | 2026-Q1 |
| OCCUDO QUANTITATIVE STRATEGIES LP trimmed | 15,100 | $114K | 0.2% | 2026-Q1 |
| Vontobel Holding Ltd. trimmed | 14,247 | $97K | 0.2% | 2026-Q1 |
| DIMENSIONAL FUND ADVISORS LP trimmed | 10,778 | $73K | 0.1% | 2026-Q1 |
| Vanguard Global Advisers, LLC new | 5,221 | $36K | 0.1% | 2026-Q1 |
| MORGAN STANLEY added | 3,493 | $24K | 0.0% | 2026-Q1 |
| FNY Investment Advisers, LLC trimmed | 3,200 | $21K | 0.0% | 2026-Q1 |
| ROYAL BANK OF CANADA trimmed | 1,699 | $11K | 0.0% | 2026-Q1 |
| Tower Research Capital LLC (TRC) added | 1,421 | $10K | 0.0% | 2026-Q1 |
| SIMPLEX TRADING, LLC added | 1,393 | $9K | 0.0% | 2026-Q1 |
| Avion Wealth new | 246 | $1K | 0.0% | 2026-Q1 |
| BNP PARIBAS FINANCIAL MARKETS | 50 | $340 | 0.0% | 2026-Q1 |
| SBI Securities Co., Ltd. | 19 | $129 | 0.0% | 2026-Q1 |
| NATIONAL BANK OF CANADA /FI/ new | 17 | $115 | 0.0% | 2026-Q1 |
| JPMORGAN CHASE & CO trimmed | 8 | $49 | 0.0% | 2026-Q1 |
| Caitong International Asset Management Co., Ltd new | 3 | $20 | 0.0% | 2026-Q1 |
| DANSKE BANK A/S | 1 | $7 | 0.0% | 2026-Q1 |
| VANGUARD GROUP INC trimmed | 291,277 | $2M | 4.4% | 2025-Q4 stale |
| GOLDMAN SACHS GROUP INC trimmed | 234,510 | $2M | 3.5% | 2025-Q4 stale |
| Aquilo Capital Management, LLC trimmed | 2,456,194 | $2M | 3.3% | 2025-Q1 stale |
| TWO SIGMA ADVISERS, LP trimmed | 111,336 | $937K | 1.7% | 2025-Q4 stale |
| Blackstone Inc. | 1,236,453 | $934K | 1.7% | 2025-Q1 stale |
| NORGES BANK | 429,550 | $619K | 1.1% | 2025-Q3 stale |
| LUMINUS MANAGEMENT LLC trimmed | 59,558 | $501K | 0.9% | 2025-Q4 stale |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC trimmed | 56,350 | $474K | 0.8% | 2025-Q4 stale |
| Squarepoint Ops LLC added | 55,723 | $469K | 0.8% | 2025-Q4 stale |
| MILLENNIUM MANAGEMENT LLC trimmed | 565,953 | $459K | 0.8% | 2025-Q3 stale |
| Schonfeld Strategic Advisors LLC trimmed | 479,108 | $388K | 0.7% | 2025-Q3 stale |
| Maven Securities LTD trimmed | 31,250 | $263K | 0.5% | 2025-Q4 stale |
| WEALTHEDGE INVESTMENT ADVISORS, LLC trimmed | 300,054 | $243K | 0.4% | 2025-Q3 stale |
| GSA CAPITAL PARTNERS LLP added | 17,763 | $150K | 0.3% | 2025-Q4 stale |
| Virtu Financial LLC added | 79,916 | $65K | 0.1% | 2025-Q3 stale |
| BLUEFIN CAPITAL MANAGEMENT, LLC new | 66,854 | $54K | 0.1% | 2025-Q3 stale |
| TANG CAPITAL MANAGEMENT LLC trimmed | 6,158 | $52K | 0.1% | 2025-Q4 stale |
| MARSHALL WACE, LLP added | 51,733 | $42K | 0.1% | 2025-Q3 stale |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP trimmed | 40,370 | $33K | 0.1% | 2025-Q3 stale |
| Abacus Planning Group, Inc. | 36,764 | $30K | 0.1% | 2025-Q3 stale |
| PRELUDE CAPITAL MANAGEMENT, LLC added | 34,247 | $26K | 0.0% | 2025-Q1 stale |
| TWO SIGMA SECURITIES, LLC added | 25,274 | $20K | 0.0% | 2025-Q3 stale |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC | 30,000 | $18K | 0.0% | 2025-Q2 stale |
| Qube Research & Technologies Ltd added | 20,257 | $16K | 0.0% | 2025-Q3 stale |
| HRT FINANCIAL LP trimmed | 18,627 | $15K | 0.0% | 2025-Q3 stale |
| D. E. Shaw & Co., Inc. trimmed | 22,199 | $14K | 0.0% | 2025-Q2 stale |
| CAXTON CORP | 17,488 | $13K | 0.0% | 2025-Q1 stale |
| Ground Swell Capital, LLC added | 15,947 | $12K | 0.0% | 2025-Q1 stale |
| Mariner, LLC new | 14,850 | $12K | 0.0% | 2025-Q3 stale |
| LANDSCAPE CAPITAL MANAGEMENT, L.L.C. new | 17,846 | $11K | 0.0% | 2025-Q2 stale |
| BANK OF AMERICA CORP /DE/ trimmed | 1,288 | $11K | 0.0% | 2025-Q4 stale |
| RAYMOND JAMES FINANCIAL INC added | 13,265 | $11K | 0.0% | 2025-Q3 stale |
| Point72 Asia (Singapore) Pte. Ltd. trimmed | 13,473 | $10K | 0.0% | 2025-Q1 stale |
| StoneX Group Inc. new | 12,448 | $9K | 0.0% | 2025-Q1 stale |
| Cubist Systematic Strategies, LLC trimmed | 12,398 | $9K | 0.0% | 2025-Q1 stale |
| COLDSTREAM CAPITAL MANAGEMENT INC new | 8,875 | $7K | 0.0% | 2025-Q1 stale |
| GROUP ONE TRADING LLC added | 6,792 | $5K | 0.0% | 2025-Q1 stale |
| HOLLENCREST CAPITAL MANAGEMENT trimmed | 250 | $2K | 0.0% | 2025-Q4 stale |
| TOTH FINANCIAL ADVISORY CORP | 1,600 | $1K | 0.0% | 2025-Q3 stale |
| Riggs Asset Managment Co. Inc. new | 1,122 | $685 | 0.0% | 2025-Q2 stale |
| FMR LLC trimmed | 34 | $286 | 0.0% | 2025-Q4 stale |
| Advisory Services Network, LLC new | 316 | $256 | 0.0% | 2025-Q3 stale |
| CITIGROUP INC trimmed | 166 | $134 | 0.0% | 2025-Q3 stale |
| Point72 (DIFC) Ltd | 95 | $72 | 0.0% | 2025-Q1 stale |
| THOMPSON INVESTMENT MANAGEMENT, INC. | 80 | $60 | 0.0% | 2025-Q1 stale |
| OSAIC HOLDINGS, INC. trimmed | 10 | $7 | 0.0% | 2025-Q3 stale |
| CONCOURSE FINANCIAL GROUP SECURITIES, INC. | 0 | — | 0.0% | 2025-Q2 stale |
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.