Q32 Bio Inc. (QTTB) Ownership
QTTB ownership summary
as of October 18, 2026- Institutions
- 87.7% of shares outstanding
- Insiders
- 2.08% of shares outstanding
- Shares outstanding
- 29.8M
- Float
- 12.7M shares available to trade
- Short interest
- 22.29% 4.7M shares short
- Days to cover
- 5.14 short interest up 23.8% vs prior month
- Institutions 87.73%
- Insiders 2.08%
- Other investors 10.20%
QTTB top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Orbimed Advisors LLC | 17.43% | 4.1M | $31.0M | +1.9M (+83.2%) | June 30, 2026 |
| 2 | Boxer Capital Management, LLC | 13.30% | 3.1M | $23.7M | +3.1M (0.0%) | June 30, 2026 |
| 3 | Atlas Venture Life Science Advisors, LLC | 11.47% | 2.7M | $20.4M | +625,000 (+29.9%) | June 30, 2026 |
| 4 | Bvf Inc | 9.92% | 2.4M | $17.7M | +2.4M (0.0%) | June 30, 2026 |
| 5 | RA Capital Management, LLC | 9.85% | 2.3M | $17.5M | +2.3M (0.0%) | June 30, 2026 |
| 6 | Point72 Asset Management, L.P. | 4.95% | 1.2M | $8.8M | +1.2M (0.0%) | June 30, 2026 |
| 7 | Opaleye Management Inc | 3.93% | 931K | $7.0M | −325,228 (−25.9%) | June 30, 2026 |
| 8 | Logos Global Management LP | 3.38% | 800K | $6.0M | +800,000 (0.0%) | June 30, 2026 |
| 9 | SummitTX Capital, L.P | 3.10% | 734K | $5.5M | +733,774 (0.0%) | June 30, 2026 |
| 10 | Vanguard Capital Management, LLC | 2.19% | 519K | $3.9M | +212,402 (+69.3%) | June 30, 2026 |
| 11 | Ikarian Capital, LLC | 1.82% | 430K | $3.2M | +430,000 (0.0%) | June 30, 2026 |
| 12 | Woodline Partners LP | 1.21% | 286K | $2.2M | +286,212 (0.0%) | June 30, 2026 |
| 13 | American Century Companies Inc | 1.15% | 273K | $2.1M | +253,982 (+1,353.1%) | June 30, 2026 |
| 14 | Sanofi | 1.03% | 244K | $1.8M | — | June 30, 2026 |
| 15 | Acadian Asset Management LLC | 0.92% | 218K | $1.6M | +45,648 (+26.4%) | June 30, 2026 |
| 16 | Renaissance Technologies Corp | 0.76% | 180K | $1.4M | −27,315 (−13.2%) | June 30, 2026 |
| 17 | Jane Street Group LLC | 0.69% | 163K | $1.2M | +97,148 (+148.1%) | June 30, 2026 |
| 18 | MONIMUS CAPITAL MANAGEMENT, LP | 0.56% | 132K | $992,911 | −2,274 (−1.7%) | June 30, 2026 |
| 19 | BOOTHBAY FUND MANAGEMENT, LLC | 0.55% | 130K | $980,811 | +130,427 (0.0%) | June 30, 2026 |
| 20 | Geode Capital Management, LLC | 0.52% | 123K | $922,629 | +4,538 (+3.8%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 16 holders added 14.5M shares and 3 cut 355K.
QTTB top mutual fund and ETF holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Vanguard MStar Total Stk Mkt Idx Invest | 3.19% | 755K | $5.7M | — | August 31, 2026 |
| 2 | Avantis US Small Cap Value ETF | 2.24% | 530K | $4.0M | — | September 30, 2026 |
| 3 | JPMorgan Small Cap Growth A | 2.08% | 494K | $3.7M | −14,555 (−2.9%) | August 31, 2026 |
| 4 | Columbia Small Cap Growth Inst | 1.46% | 346K | $2.6M | +345,928 (0.0%) | August 31, 2026 |
| 5 | MEDICAL BioHealth EUR Acc | 0.76% | 181K | $1.4M | +38 (+0.0%) | August 31, 2026 |
| 6 | JPMorgan Small Cap Blend A | 0.67% | 158K | $1.2M | −2,907 (−1.8%) | August 31, 2026 |
| 7 | First Trust Dow Jones Sel MicroCap ETF | 0.38% | 89K | $670,288 | — | September 30, 2026 |
| 8 | Multi-Manager Small Cap Eq Strat Inst | 0.28% | 66K | $499,486 | −13,863 (−17.3%) | August 31, 2026 |
| 9 | JPM US Small Cap Growth A dist USD | 0.23% | 55K | $417,104 | −336 (−0.6%) | August 31, 2026 |
| 10 | Fidelity Extended Market Index | 0.21% | 51K | $381,580 | −273 (−0.5%) | August 31, 2026 |
| 11 | Avantis® U.S. Small Cap Value Instl | 0.21% | 51K | $380,723 | +34,794 (+219.7%) | August 31, 2026 |
| 12 | Truvalue Glb Phrmctl Blgcl Eq (QDII) A | 0.20% | 47K | $355,320 | +47,250 (0.0%) | June 30, 2026 |
| 13 | Dimensional US Small Cap ETF | 0.17% | 41K | $307,545 | — | September 30, 2026 |
| 14 | JPM US Small Cap Growth C Acc | 0.16% | 37K | $281,413 | −4 (−0.0%) | August 31, 2026 |
| 15 | Bridgeway Ultra-Small Company | 0.15% | 35K | $260,290 | +22,000 (+174.4%) | June 30, 2026 |
| 16 | iShares Micro-Cap ETF | 0.13% | 30K | $229,082 | −210 (−0.7%) | September 30, 2026 |
| 17 | JHVIT Health Sciences I | 0.12% | 29K | $218,817 | — | August 31, 2026 |
| 18 | Avantis US Small Cap Equity ETF | 0.11% | 27K | $204,476 | +170 (+0.6%) | September 30, 2026 |
| 19 | JPMorgan American Ord | 0.11% | 25K | $188,948 | +25,126 (0.0%) | July 31, 2026 |
| 20 | Fidelity Nasdaq Composite Index | 0.10% | 24K | $178,931 | +9,708 (+68.9%) | August 31, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
QTTB insider transactions
latest 8| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2026-02-25 | Jodie Pope Morrison | Sell | $4.51 | 9,896 | $44,631 |
| 2026-02-25 | Lee Kalowski | Sell | $4.51 | 3,995 | $18,017 |
| 2026-02-25 | Shelia M Violette | Sell | $4.51 | 2,815 | $12,696 |
| 2025-12-02 | Jodie Pope Morrison | Sell | $3.46 | 22,506 | $77,871 |
| 2025-12-02 | Lee Kalowski | Sell | $3.46 | 9,072 | $31,389 |
| 2025-08-26 | Jodie Pope Morrison | Sell | $1.80 | 10,494 | $18,889 |
| 2025-08-26 | Lee Kalowski | Sell | $1.80 | 4,240 | $7,632 |
| 2025-08-26 | Shelia M Violette | Sell | $1.80 | 2,990 | $5,382 |
Reported trades by company officers, directors and other filers (including disclosures by members of Congress where EODHD lists them). "—" where the filing gives no share count.
QTTB shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns QTTB
Institutional investors own 87.7% of Q32 Bio's shares and insiders 2.08%. The largest holder is Orbimed Advisors LLC with 17.43% of the shares (4.1M), as of June 30, 2026. Among the top 20 institutions, 16 added shares and 3 reduced their stake in the latest filings. Short interest is 22.29% of the float, or 5.14 days of average trading volume. The share count rose 535.0% since 2017.
Related: QTTB analyst forecast, QTTB key metrics. See the QTTB stock overview for the latest quote and news.
QTTB ownership FAQ
Who owns the most Q32 Bio stock?
The largest shareholders of Q32 Bio are Orbimed Advisors LLC (17.43%), Boxer Capital Management, LLC (13.30%), Atlas Venture Life Science Advisors, LLC (11.47%), Bvf Inc (9.92%), RA Capital Management, LLC (9.85%).
What percentage of Q32 Bio is owned by institutions?
Institutions hold 87.7% of Q32 Bio's shares outstanding; insiders hold 2.08%.
Which funds own Q32 Bio?
The largest fund holders of Q32 Bio are Vanguard MStar Total Stk Mkt Idx Invest (3.19%), Avantis US Small Cap Value ETF (2.24%), JPMorgan Small Cap Growth A (2.08%), Columbia Small Cap Growth Inst (1.46%), MEDICAL BioHealth EUR Acc (0.76%).
What is Q32 Bio's short interest?
4.7M shares of Q32 Bio were sold short, 22.29% of the float; at the average daily volume it would take 5.14 days to cover.
Are insiders buying or selling Q32 Bio?
Of the latest 8 reported insider transactions in Q32 Bio (since August 26, 2025), 0 were purchases and 8 were sales.
How many shares of Q32 Bio are outstanding?
Q32 Bio has 29.8M shares outstanding, of which 12.7M are in the public float.