52% buyers of institutions opening or closing positions this quarter
1 more new buyers than exits, ownership rose 7.38 percentage points vs the prior quarter, and 3 well-known fund managers in the top 25.
52% buyers of institutions opening or closing positions this quarter
36.5% institutional ownership
Atlas Venture Life portfolio allocation
Institutional ownership vs Biotechnology peers
No Form 4 insider transactions on file
Latest positioning in QTTB across 13F flow, ownership shift, marquee holders, and holder-count growth.
Ranked by reported Q1 2026 13F market value
Share of total reported institutional value in QTTB held by the largest 10 / 25 filers.
| # | Institution | Shares Held | Market Value | QoQ Change | Ownership % | % of Fund |
|---|---|---|---|---|---|---|
| 1 | ORBIMED ADVISORS LLC | 2.3M | $14.5M | 0.0% | 17.634% | 0.29% |
| 2 | Atlas Venture Life Science Advisors, LLC | 2.1M | $13.4M | 0.0% | 16.375% | 1.70% |
| 3 | Opaleye Management Inc. | 1.3M | $8.1M | +488.8% | 9.832% | 1.06% |
| 4 | Carlyle Group Inc. | 1.1M | $7.1M | 0.0% | 8.631% | 0.07% |
| 5 | ARCH Venture Management, LLC | 320K | $2.1M | 0.0% | 2.508% | 0.30% |
| 6 | ACORN CAPITAL ADVISORS, LLC | 315K | $2.0M | -36.1% | 2.466% | 0.57% |
| 7 | VANGUARD CAPITAL MANAGEMENT LLC | 306K | $2.0M | β | 2.398% | 0.00% |
| 8 | MACKENZIE FINANCIAL CORP | 246K | $1.6M | β | 1.928% | 0.00% |
| 9 | Sanofi | 244K | $1.6M | 0.0% | 1.910% | 0.47% |
| 10 | RENAISSANCE TECHNOLOGIES LLC | 207K | $1.3M | +107.7% | 1.620% | 0.00% |
| 11 | MONIMUS CAPITAL MANAGEMENT, LP | 134K | $862K | β | 1.051% | 0.24% |
| 12 | GEODE CAPITAL MANAGEMENT, LLC | 118K | $759K | +11.3% | 0.925% | 0.00% |
| 13 | PFIZER INC | 102K | $737K | -63.4% | 0.795% | 0.31% |
| 14 | BlackRock, Inc. | 86K | $553K | +43.7% | 0.674% | 0.00% |
| 15 | JANE STREET GROUP, LLC | 66K | $421K | +158.5% | 0.513% | 0.00% |
| 16 | MARSHALL WACE, LLP | 52K | $337K | β | 0.410% | 0.00% |
| 17 | VANGUARD FIDUCIARY TRUST CO | 50K | $321K | β | 0.391% | 0.00% |
| 18 | TWO SIGMA INVESTMENTS, LP | 42K | $272K | -9.6% | 0.331% | 0.00% |
| 19 | STATE STREET CORP | 42K | $267K | +95.5% | 0.325% | 0.00% |
| 20 | ADAR1 Capital Management, LLC | 35K | $225K | +75.0% | 0.274% | 0.01% |
| 21 | Affinity Asset Advisors, LLC | 28K | $178K | 0.0% | 0.217% | 0.01% |
| 22 | NORTHERN TRUST CORP | 25K | $161K | 0.0% | 0.196% | 0.00% |
| 23 | Cetera Investment Advisers | 21K | $133K | β | 0.162% | 0.00% |
| 24 | AMERICAN CENTURY COMPANIES INC | 19K | $121K | β | 0.147% | 0.00% |
| 25 | CITADEL ADVISORS LLC | 15K | $99K | -66.1% | 0.121% | 0.00% |
denotes a marquee investor (Buffett, Burry, ARK, Tiger Global, Pershing Square, Baupost and other widely-followed managers). β% of Fundβ shows how much of that investorβs total 13F portfolio is invested in QTTB β a direct measure of their conviction.
Filings activity in QTTB during Q1 2026, grouped by how each filer changed its position.
8 quarters of 13F filings Β· Ξ columns show change vs prior quarter
| Quarter | Inst. Holders | Ξ Holders | Ownership % | Ξ Ownership | Total 13F Value | Ξ Value |
|---|---|---|---|---|---|---|
| Q1 2026 | 53 | +1.9% | 36.55% | +7.38 pp | $59M | +124% |
| Q4 2025 | 52 | +0.0% | 29.17% | +10.91 pp | $26M | +60% |
| Q3 2025 | 52 | 12% | 18.26% | +3.58 pp | $17M | +24% |
| Q2 2025 | 59 | 18% | 14.68% | +5.17 pp | $13M | 14% |
| Q1 2025 | 72 | 20% | 9.51% | 32.33 pp | $15M | 59% |
| Q4 2024 | 90 | +23% | 41.84% | 158.15 pp | $38M | 91% |
| Q3 2024 | 73 | +38% | 199.99% | +42.01 pp | $406M | +184% |
| Q2 2024 | 53 | β | 157.98% | β | $143M | β |
Source: SEC 13F institutional filings. Ownership % requires market cap data and will show once linked. Ξ columns compare to the immediately prior filed quarter.
No recent Form 4 insider transactions on file for QTTB.
Quick answers to the most common questions about buying QTTB stock.
Based on Q1 2026 13F filings, institutional ownership of Q32 Bio Inc. stands at 36.5%, held across 53 reporting institutions.
ORBIMED ADVISORS LLC is the largest reported institutional holder of QTTB, with approximately 2,252,987 shares worth $0.01B as of Q1 2026.
Yes β 3 widely-followed marquee investors appear among the top 25 institutional holders of QTTB, including RENAISSANCE TECHNOLOGIES LLC, TWO SIGMA INVESTMENTS, LP, CITADEL ADVISORS LLC.
Our composite Smart Money Score for QTTB is 72 out of 100 (Bullish). It combines net institutional buying activity, ownership shift, marquee investor presence, and holder-count growth.
12 institutions opened new positions in QTTB during Q1 2026, while 11 fully exited. 37 added to existing positions and 3 trimmed.
QTTB institutional ownership rose by 7.38 percentage points quarter-over-quarter, with a net change of +1 holders.
The top 10 institutions account for 90.3% of all reported 13F value in QTTB, and the top 25 account for 99.5%.
All data is sourced from SEC Form 13F filings, which institutional investment managers with at least $100M in assets are required to file each quarter. We process every 13F filing from EDGAR and recompute the aggregates after each cycle. Insider transactions are sourced from Form 4 filings.