Definium Therapeutics, Inc. (DFTX) Ownership
DFTX ownership summary
as of October 18, 2026- Institutions
- 88.4% of shares outstanding
- Insiders
- 2.57% of shares outstanding
- Shares outstanding
- 134.4M
- Float
- 125.5M shares available to trade
- Short interest
- 8.50% 11.3M shares short
- Days to cover
- 4.80 short interest down 3.7% vs prior month
- Institutions 88.35%
- Insiders 2.57%
- Other investors 9.08%
DFTX top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | BlackRock Inc | 8.36% | 11.2M | $360.6M | +2.8M (+32.5%) | June 30, 2026 |
| 2 | venBio Select Advisor LLC | 5.35% | 7.2M | $230.8M | +2.2M (+43.8%) | June 30, 2026 |
| 3 | Driehaus Capital Management LLC | 5.09% | 6.8M | $219.7M | +933,387 (+15.8%) | June 30, 2026 |
| 4 | Jupiter Topco LLC | 4.18% | 5.6M | $180.3M | +5.6M (0.0%) | June 30, 2026 |
| 5 | Capital World Investors | 3.99% | 5.4M | $172.3M | +5.4M (0.0%) | June 30, 2026 |
| 6 | FMR Inc | 3.54% | 4.8M | $152.6M | +2.9M (+162.6%) | June 30, 2026 |
| 7 | T. Rowe Price Associates, Inc. | 3.46% | 4.7M | $149.3M | +4.6M (+6,545.7%) | June 30, 2026 |
| 8 | Geode Capital Management, LLC | 2.71% | 3.6M | $117.0M | +1.1M (+46.1%) | June 30, 2026 |
| 9 | HHG PLC | 2.65% | 3.6M | $114.1M | +1.1M (+47.4%) | March 31, 2026 |
| 10 | State Street Corp | 2.28% | 3.1M | $98.4M | +593,517 (+24.0%) | June 30, 2026 |
| 11 | Capital Research & Mgmt Co - Division 3 | 2.21% | 3.0M | $95.1M | +3.0M (0.0%) | June 30, 2026 |
| 12 | Octagon Capital Advisors LP | 2.20% | 3.0M | $94.7M | +510,000 (+20.9%) | June 30, 2026 |
| 13 | Wellington Management Company LLP | 2.20% | 2.9M | $94.7M | +1.6M (+126.1%) | June 30, 2026 |
| 14 | Deep Track Capital, LP | 2.05% | 2.8M | $88.3M | −250,000 (−8.3%) | June 30, 2026 |
| 15 | COMMODORE CAPITAL LP | 1.49% | 2.0M | $64.2M | — | June 30, 2026 |
| 16 | AllianceBernstein L.P. | 1.34% | 1.8M | $57.9M | +1.7M (+1,866.4%) | June 30, 2026 |
| 17 | The Goldman Sachs Group Inc | 1.34% | 1.8M | $57.8M | +125,441 (+7.5%) | June 30, 2026 |
| 18 | Citadel Advisors Llc | 1.26% | 1.7M | $54.2M | +355,145 (+26.6%) | June 30, 2026 |
| 19 | Vanguard Portfolio Management, LLC | 1.23% | 1.6M | $52.9M | +775,761 (+88.9%) | June 30, 2026 |
| 20 | RA Capital Management, LLC | 1.12% | 1.5M | $48.1M | +1.5M (0.0%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 18 holders added 36.9M shares and 1 cut 250K.
DFTX top mutual fund and ETF holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | American Funds SMALLCAP World A | 5.72% | 7.7M | $246.8M | +7.7M (0.0%) | June 30, 2026 |
| 2 | iShares Russell 2000 ETF | 2.41% | 3.2M | $104.1M | −27,470 (−0.8%) | September 30, 2026 |
| 3 | Fidelity Small Cap Index | 1.06% | 1.4M | $45.7M | +11,962 (+0.8%) | July 31, 2026 |
| 4 | T. Rowe Price New Horizons | 0.91% | 1.2M | $39.1M | −49,752 (−3.9%) | August 31, 2026 |
| 5 | iShares Russell 2000 Growth ETF | 0.87% | 1.2M | $37.6M | −1,482 (−0.1%) | September 30, 2026 |
| 6 | iShares Biotechnology ETF | 0.74% | 1.0M | $32.1M | −7,576 (−0.8%) | September 30, 2026 |
| 7 | Candriam Eqs L Biotech C USD Cap | 0.72% | 971K | $31.2M | — | March 31, 2026 |
| 8 | T. Rowe Price Health Sciences | 0.72% | 963K | $30.9M | −507,700 (−34.5%) | August 31, 2026 |
| 9 | T. Rowe Price Integrated US Sm Gr Eq | 0.67% | 901K | $28.9M | — | August 31, 2026 |
| 10 | Janus Henderson Hrzn Biotec E2 USD | 0.65% | 873K | $28.0M | +83,126 (+10.5%) | June 30, 2026 |
| 11 | Fidelity Small Cap Growth | 0.58% | 779K | $25.0M | −38,004 (−4.6%) | July 31, 2026 |
| 12 | Heptagon Driehaus US Micro Cap Eq C$ Acc | 0.57% | 772K | $24.8M | — | August 31, 2026 |
| 13 | Janus Henderson Global Life Sciences D | 0.57% | 766K | $24.6M | +55,349 (+7.8%) | August 31, 2026 |
| 14 | Vanguard Russell 2000 ETF | 0.56% | 748K | $24.0M | +17,658 (+2.4%) | August 31, 2026 |
| 15 | Vanguard Health Care Inv | 0.55% | 741K | $23.8M | +740,600 (0.0%) | June 30, 2026 |
| 16 | Polar Capital Biotech S Inc | 0.55% | 735K | $23.6M | — | August 31, 2026 |
| 17 | Janus Henderson Glb Life Scn I2 USD | 0.54% | 731K | $23.5M | +52,391 (+7.7%) | August 31, 2026 |
| 18 | Eventide Healthcare & Life Sciences I | 0.53% | 710K | $22.8M | +23,838 (+3.5%) | June 30, 2026 |
| 19 | Schwab US Small-Cap ETF™ | 0.53% | 707K | $22.7M | +477 (+0.1%) | September 30, 2026 |
| 20 | Janus Global Life Science AUSD | 0.51% | 679K | $21.8M | +678,642 (0.0%) | June 30, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
DFTX insider transactions
latest 9| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2025-12-26 | Daniel Karlin | Sell | $13.15 | 5,600 | $73,640 |
| 2025-12-26 | Mark Sullivan | Sell | $13.15 | 11,276 | $148,279 |
| 2025-12-26 | Robert Barrow | Sell | $13.15 | 25,791 | $339,152 |
| 2025-09-25 | Daniel Karlin | Sell | $9.77 | 7,704 | $75,268 |
| 2025-09-25 | Mark Sullivan | Sell | $9.77 | 11,278 | $110,186 |
| 2025-09-25 | Robert Barrow | Sell | $9.77 | 25,797 | $252,037 |
| 2025-06-25 | Daniel Karlin | Sell | $6.80 | 7,848 | $53,366 |
| 2025-06-25 | Mark Sullivan | Sell | $6.80 | 11,491 | $78,139 |
| 2025-06-25 | Robert Barrow | Sell | $6.80 | 26,491 | $180,139 |
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.
DFTX shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns DFTX
Institutional investors own 88.4% of Definium Therapeutics's shares and insiders 2.57%. The largest holder is BlackRock Inc with 8.36% of the shares (11.2M), as of June 30, 2026. Among the top 20 institutions, 18 added shares and 1 reduced their stake in the latest filings. Short interest is 8.50% of the float, or 4.80 days of average trading volume. The share count rose 43,326.2% since 2016.
Related: DFTX analyst forecast, DFTX key metrics. See the DFTX stock overview for the latest quote and news.
DFTX ownership FAQ
Who owns the most Definium Therapeutics stock?
The largest shareholders of Definium Therapeutics are BlackRock Inc (8.36%), venBio Select Advisor LLC (5.35%), Driehaus Capital Management LLC (5.09%), Jupiter Topco LLC (4.18%), Capital World Investors (3.99%).
What percentage of Definium Therapeutics is owned by institutions?
Institutions hold 88.4% of Definium Therapeutics's shares outstanding; insiders hold 2.57%.
Which funds own Definium Therapeutics?
The largest fund holders of Definium Therapeutics are American Funds SMALLCAP World A (5.72%), iShares Russell 2000 ETF (2.41%), Fidelity Small Cap Index (1.06%), T. Rowe Price New Horizons (0.91%), iShares Russell 2000 Growth ETF (0.87%).
What is Definium Therapeutics's short interest?
11.3M shares of Definium Therapeutics were sold short, 8.50% of the float; at the average daily volume it would take 4.80 days to cover.
Are insiders buying or selling Definium Therapeutics?
Of the latest 9 reported insider transactions in Definium Therapeutics (since June 25, 2025), 0 were purchases and 9 were sales.
How many shares of Definium Therapeutics are outstanding?
Definium Therapeutics has 134.4M shares outstanding, of which 125.5M are in the public float.