Who owns Q32 Bio Inc. (QTTB)
Which tracked institutional funds hold QTTB, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See QTTB company fundamentals →
Ownership as of the 2026-Q1 13F filings (latest filed 2026-05-18). 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 QTTB is one-sided between 2025-Q4 and 2026-Q1: 15 added or opened and 1 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
QTTB’s largest tracked holder by dollar value, ORBIMED ADVISORS LLC, sizes it at 0.3% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 0.3pp conviction gap — its largest holder concentrates the name more heavily than the typical one.
Book-share is each fund’s reported value in QTTB 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 53 tracked filers holding QTTB, 25 increased or opened the position and 20 reduced or closed it; over the same quarter, open-market insider Form 4 buying and selling roughly offset.
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 QTTB 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 3
- VANGUARD CAPITAL MANAGEMENT LLC$2M
- MACKENZIE FINANCIAL CORP$2M
- MONIMUS CAPITAL MANAGEMENT, LP$862K
Full exits 1
- VANGUARD GROUP INC$1M
Largest adds
- Opaleye Management Inc.$7M
- ORBIMED ADVISORS LLC$7M
- Atlas Venture Life Science Advisors, LLC$6M
- Carlyle Group Inc.$3M
- RENAISSANCE TECHNOLOGIES LLC$998K
- ARCH Venture Management, LLC$993K
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 |
|---|---|---|---|---|
| ORBIMED ADVISORS LLC | 2,252,987 | $14M | 22.9% | 2026-Q1 |
| Atlas Venture Life Science Advisors, LLC | 2,092,106 | $13M | 21.3% | 2026-Q1 |
| Opaleye Management Inc. added | 1,256,228 | $8M | 12.8% | 2026-Q1 |
| Carlyle Group Inc. | 1,102,741 | $7M | 11.2% | 2026-Q1 |
| ARCH Venture Management, LLC | 320,482 | $2M | 3.3% | 2026-Q1 |
| ACORN CAPITAL ADVISORS, LLC trimmed | 315,052 | $2M | 3.2% | 2026-Q1 |
| VANGUARD CAPITAL MANAGEMENT LLC new | 306,401 | $2M | 3.1% | 2026-Q1 |
| MACKENZIE FINANCIAL CORP new | 246,304 | $2M | 2.5% | 2026-Q1 |
| Sanofi | 244,083 | $2M | 2.5% | 2026-Q1 |
| RENAISSANCE TECHNOLOGIES LLC added | 206,915 | $1M | 2.1% | 2026-Q1 |
| ACADIAN ASSET MANAGEMENT LLC added | 172,586 | $1M | 1.8% | 2026-Q1 |
| MONIMUS CAPITAL MANAGEMENT, LP new | 134,310 | $862K | 1.4% | 2026-Q1 |
| GEODE CAPITAL MANAGEMENT, LLC added | 118,152 | $759K | 1.2% | 2026-Q1 |
| Pfizer Inc trimmed | 101,618 | $737K | 1.2% | 2026-Q1 |
| BlackRock, Inc. added | 86,147 | $553K | 0.9% | 2026-Q1 |
| JANE STREET GROUP, LLC added | 65,599 | $421K | 0.7% | 2026-Q1 |
| MARSHALL WACE, LLP added | 52,408 | $336K | 0.5% | 2026-Q1 |
| VANGUARD FIDUCIARY TRUST CO new | 49,995 | $321K | 0.5% | 2026-Q1 |
| TWO SIGMA INVESTMENTS, LP trimmed | 42,346 | $272K | 0.4% | 2026-Q1 |
| STATE STREET CORP added | 41,514 | $267K | 0.4% | 2026-Q1 |
| Cambridge Investment Research Advisors, Inc. new | 35,025 | $225K | 0.4% | 2026-Q1 |
| ADAR1 Capital Management, LLC added | 35,000 | $225K | 0.4% | 2026-Q1 |
| Affinity Asset Advisors, LLC | 27,777 | $178K | 0.3% | 2026-Q1 |
| NORTHERN TRUST CORP | 25,033 | $161K | 0.3% | 2026-Q1 |
| Cetera Investment Advisers new | 20,695 | $133K | 0.2% | 2026-Q1 |
| AMERICAN CENTURY COMPANIES INC new | 18,770 | $121K | 0.2% | 2026-Q1 |
| CITADEL ADVISORS LLC trimmed | 15,481 | $99K | 0.2% | 2026-Q1 |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC new | 12,613 | $81K | 0.1% | 2026-Q1 |
| MORGAN STANLEY added | 9,560 | $61K | 0.1% | 2026-Q1 |
| EverSource Wealth Advisors, LLC trimmed | 1,110 | $48K | 0.1% | 2026-Q1 |
| FMR LLC added | 3,400 | $22K | 0.0% | 2026-Q1 |
| ROYAL BANK OF CANADA added | 2,744 | $18K | 0.0% | 2026-Q1 |
| FEDERATED HERMES, INC. | 2,273 | $15K | 0.0% | 2026-Q1 |
| Vanguard Global Advisers, LLC new | 1,915 | $12K | 0.0% | 2026-Q1 |
| Tower Research Capital LLC (TRC) added | 1,871 | $12K | 0.0% | 2026-Q1 |
| Arax Advisory Partners added | 1,148 | $7K | 0.0% | 2026-Q1 |
| Rockefeller Capital Management L.P. | 577 | $4K | 0.0% | 2026-Q1 |
| JONES FINANCIAL COMPANIES LLLP | 500 | $4K | 0.0% | 2026-Q1 |
| Russell Investments Group, Ltd. | 454 | $3K | 0.0% | 2026-Q1 |
| BNP PARIBAS FINANCIAL MARKETS trimmed | 303 | $2K | 0.0% | 2026-Q1 |
| UBS Group AG trimmed | 270 | $2K | 0.0% | 2026-Q1 |
| NISA INVESTMENT ADVISORS, LLC | 166 | $1K | 0.0% | 2026-Q1 |
| OSAIC HOLDINGS, INC. trimmed | 124 | $796 | 0.0% | 2026-Q1 |
| NORTHWESTERN MUTUAL WEALTH MANAGEMENT CO added | 111 | $713 | 0.0% | 2026-Q1 |
| SBI Securities Co., Ltd. trimmed | 104 | $668 | 0.0% | 2026-Q1 |
| Allworth Financial LP | 98 | $630 | 0.0% | 2026-Q1 |
| WELLS FARGO & COMPANY/MN trimmed | 84 | $539 | 0.0% | 2026-Q1 |
| Federation des caisses Desjardins du Quebec | 70 | $446 | 0.0% | 2026-Q1 |
| CWM, LLC trimmed | 39 | $250 | 0.0% | 2026-Q1 |
| GROUP ONE TRADING LLC | 34 | $218 | 0.0% | 2026-Q1 |
| HARBOUR INVESTMENTS, INC. | 11 | $71 | 0.0% | 2026-Q1 |
| AdvisorNet Financial, Inc | 2 | $13 | 0.0% | 2026-Q1 |
| VANGUARD GROUP INC added | 321,051 | $1M | 1.7% | 2025-Q4 stale |
| Trustees of Columbia University in the City of New York | 133,903 | $265K | 0.4% | 2025-Q3 stale |
| MILLENNIUM MANAGEMENT LLC trimmed | 51,268 | $170K | 0.3% | 2025-Q4 stale |
| Monaco Asset Management SAM trimmed | 50,919 | $169K | 0.3% | 2025-Q4 stale |
| GOLDMAN SACHS GROUP INC added | 63,539 | $95K | 0.2% | 2025-Q2 stale |
| Nuveen, LLC new | 55,886 | $92K | 0.1% | 2025-Q1 stale |
| HRT FINANCIAL LP added | 24,698 | $81K | 0.1% | 2025-Q4 stale |
| XTX Topco Ltd new | 20,353 | $68K | 0.1% | 2025-Q4 stale |
| Scientech Research LLC new | 15,510 | $51K | 0.1% | 2025-Q4 stale |
| DEUTSCHE BANK AG\ | 25,018 | $41K | 0.1% | 2025-Q1 stale |
| AQR CAPITAL MANAGEMENT LLC trimmed | 26,530 | $40K | 0.1% | 2025-Q2 stale |
| TWO SIGMA SECURITIES, LLC new | 13,749 | $27K | 0.0% | 2025-Q3 stale |
| Bank of New York Mellon Corp added | 16,192 | $27K | 0.0% | 2025-Q1 stale |
| Squarepoint Ops LLC trimmed | 14,528 | $24K | 0.0% | 2025-Q1 stale |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC trimmed | 14,190 | $23K | 0.0% | 2025-Q1 stale |
| DLK Investment Management, LLC | 10,333 | $20K | 0.0% | 2025-Q3 stale |
| OPPENHEIMER & CO INC new | 13,000 | $19K | 0.0% | 2025-Q2 stale |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP added | 12,909 | $19K | 0.0% | 2025-Q2 stale |
| Corton Capital Inc. new | 11,607 | $19K | 0.0% | 2025-Q1 stale |
| RHUMBLINE ADVISERS trimmed | 11,156 | $18K | 0.0% | 2025-Q1 stale |
| Mariner, LLC trimmed | 11,780 | $18K | 0.0% | 2025-Q2 stale |
| RAYMOND JAMES FINANCIAL INC | 10,746 | $16K | 0.0% | 2025-Q2 stale |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. added | 3,619 | $6K | 0.0% | 2025-Q1 stale |
| Global Retirement Partners, LLC trimmed | 1,500 | $5K | 0.0% | 2025-Q4 stale |
| Corebridge Financial, Inc. trimmed | 2,986 | $5K | 0.0% | 2025-Q1 stale |
| China Universal Asset Management Co., Ltd. trimmed | 2,138 | $4K | 0.0% | 2025-Q3 stale |
| NEW YORK STATE COMMON RETIREMENT FUND | 2,400 | $4K | 0.0% | 2025-Q1 stale |
| BANK OF AMERICA CORP /DE/ trimmed | 1,035 | $3K | 0.0% | 2025-Q4 stale |
| Police & Firemen's Retirement System of New Jersey | 1,228 | $2K | 0.0% | 2025-Q1 stale |
| COLDSTREAM CAPITAL MANAGEMENT INC new | 1,114 | $2K | 0.0% | 2025-Q1 stale |
| JPMORGAN CHASE & CO added | 324 | $1K | 0.0% | 2025-Q4 stale |
| SIMPLEX TRADING, LLC new | 813 | $1K | 0.0% | 2025-Q2 stale |
| Ameritas Investment Partners, Inc. | 591 | $975 | 0.0% | 2025-Q1 stale |
| Mirae Asset Global Investments Co., Ltd. added | 472 | $935 | 0.0% | 2025-Q3 stale |
| Fortitude Family Office, LLC | 562 | $927 | 0.0% | 2025-Q1 stale |
| Legal & General Group Plc | 523 | $863 | 0.0% | 2025-Q1 stale |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM | 437 | $721 | 0.0% | 2025-Q1 stale |
| CITIGROUP INC trimmed | 236 | $467 | 0.0% | 2025-Q3 stale |
| GF FUND MANAGEMENT CO. LTD. trimmed | 227 | $449 | 0.0% | 2025-Q3 stale |
| Clark Wealth Partners | 199 | $297 | 0.0% | 2025-Q2 stale |
| CoreCap Advisors, LLC | 107 | $177 | 0.0% | 2025-Q1 stale |
| Sterling Capital Management LLC trimmed | 105 | $173 | 0.0% | 2025-Q1 stale |
| True Wealth Design, LLC added | 67 | $100 | 0.0% | 2025-Q2 stale |
| BARCLAYS PLC trimmed | 19 | $63 | 0.0% | 2025-Q4 stale |
| ST GERMAIN D J CO INC | 11 | $22 | 0.0% | 2025-Q3 stale |
| Farther Finance Advisors, LLC | 6 | $9 | 0.0% | 2025-Q1 stale |
| Essential Partners LLC new | 5 | $7 | 0.0% | 2025-Q2 stale |
| THOMPSON INVESTMENT MANAGEMENT, INC. | 4 | $7 | 0.0% | 2025-Q1 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.