DFTXNasdaqMedicinal Chemicals & Botanical ProductsFiscal year ends December 31
Definium Therapeutics, Inc.
Financials through Q2 FY2026, quarter ended Jun 30, 2026Last filing: 10-Q on Aug 6, 2026
$32.97+0.87 (+2.71%)
Close on Oct 19, 2026
- Market cap
- $3.65B
- P/E (TTM)
- –
- Dividend yield
- –
Ownership
Institutional holdings as of Jun 30, 2026, from 13F filings
Held by institutions
85.4%
115M of 134M shares
Institutional holders
360
149 new, 29 sold out
Net institutional buying
40M
In Q2 2026
Insider trades, 12 months
0 buys · 17 sales
Net sold $7.00M
Shares held by institutions
Holders of more than 5%
Latest Schedule 13D (active) or 13G (passive) filed by each holder
| Holder | Shares | % of class | Filing | As of |
|---|---|---|---|---|
| Commodore Capital Master LP | 7,428,775 | 7.20% | 13G (passive) amendment | Dec 31, 2025 |
| Driehaus Capital Management LLC | 6,845,276 | 5.36% | 13G (passive) amendment | Jun 30, 2026 |
| BlackRock, Inc. | 6,070,053 | 8.30% | 13G (passive) amendment | Dec 31, 2024 |
| Deep Track Capital, LP | 5,676,540 | 5.54% | 13G (passive) amendment | Dec 31, 2025 |
| Behzad Aghazadeh | 5,000,000 | 5.08% | 13G (passive) | Dec 31, 2025 |
Top institutional holders
13F holdings as of Jun 30, 2026
| Holder | Shares | % of DFTX | Value | Change | % of portfolio |
|---|---|---|---|---|---|
| BlackRock, Inc. | 11,232,834 | 8.36% | $528.39M | +2,752,604 | 0.01% |
| Avoro Capital Advisors LLC | 7,188,888 | 5.35% | $338.17M | +2,188,888 | 3.04% |
| Driehaus Capital Management LLC | 6,845,276 | 5.09% | $322.00M | +933,387 | 1.87% |
| Jupiter Topco LLC | 5,615,645 | 4.18% | $264.00M | New | 0.11% |
| Capital World Investors | 5,367,723 | 3.99% | $252.50M | New | 0.03% |
| FMR LLC | 4,752,921 | 3.54% | $223.58M | +2,943,311 | 0.01% |
| Price T Rowe Associates Inc /Md/ | 4,652,032 | 3.46% | $218.83K | +4,582,031 | 0.02% |
| Geode Capital Management, LLC | 3,644,813 | 2.71% | $171.48M | +1,149,414 | 0.01% |
| State Street Corp | 3,065,390 | 2.28% | $144.20M | +593,517 | 0.00% |
| Capital International Investors | 2,963,410 | 2.21% | $139.40M | New | 0.03% |
| Octagon Capital Advisors LP | 2,950,000 | 2.20% | $138.77M | +510,000 | 12.47% |
| Wellington Management Group Llp | 2,949,734 | 2.20% | $138.76M | +1,644,985 | 0.02% |
| Deep Track Capital, LP | 2,750,000 | 2.05% | $129.36M | −250,000 | 1.88% |
| Commodore Capital LP | 2,000,000 | 1.49% | $94.08M | – | 5.60% |
| Alliancebernstein L.P. | 1,803,287 | 1.34% | $34.08M | +1,711,584 | 0.01% |
| Goldman Sachs Group Inc | 1,800,852 | 1.34% | $84.71M | +125,441 | 0.01% |
| Citadel Advisors LLC | 1,688,587 | 1.26% | $79.43M | +355,145 | 0.01% |
| Vanguard Portfolio Management LLC | 1,648,426 | 1.23% | $77.54M | +775,761 | 0.00% |
| Ra Capital Management, L.P. | 1,500,000 | 1.12% | $70.56M | New | 0.61% |
| Vanguard Capital Management LLC | 1,486,454 | 1.11% | $69.92M | +389,476 | 0.00% |
Institutional buying and selling by quarter
Positions opened, added to, reduced and closed by 13F filers
| Quarter | Holders | Shares held | % of shares | New / added | Reduced / closed | Shares bought | Shares sold |
|---|---|---|---|---|---|---|---|
| Q2 2026 | 360 | 115M | 85.4% | 149 / 116 | 64 / 29 | 50M | 10M |
| Q1 2026 | 245 | 78M | 58.3% | 238 / 2 | 4 / 1 | 70M | 3M |
| Q4 2025 | 8 | 11M | 8.4% | 8 / 0 | 0 / 0 | 11M | 0M |
Top mutual fund and ETF holders
Latest monthly portfolio reports (Form N-PORT)
| Fund | Shares | % of DFTX | Value | % of fund | As of |
|---|---|---|---|---|---|
| SMALLCAP World Fund Inc | 7,689,008 | 5.72% | $361.69M | 0.38% | Jun 30, 2026 |
| iShares Russell 2000 ETF | 3,347,307 | 2.49% | $157.46M | 0.19% | Jun 30, 2026 |
| Vanguard Extended Market Index Fund | 1,486,832 | 1.11% | $69.94M | 0.07% | Jun 30, 2026 |
| Fidelity Small Cap Index Fund | 1,422,899 | 1.06% | $61.92M | 0.18% | Jul 31, 2026 |
| T. Rowe Price Health Sciences Fund, Inc. | 1,287,318 | 0.96% | $60.56M | 0.51% | Jun 30, 2026 |
| iShares Russell 2000 Growth ETF | 1,188,581 | 0.88% | $55.91M | 0.36% | Jun 30, 2026 |
| T. Rowe Price New Horizons Fund, Inc. | 1,141,178 | 0.85% | $53.68M | 0.36% | Jun 30, 2026 |
| Fidelity Small Cap Growth Fund | 779,396 | 0.58% | $33.92M | 0.39% | Jul 31, 2026 |
| iShares Biotechnology ETF | 743,400 | 0.55% | $34.97M | 0.38% | Jun 30, 2026 |
| Vanguard Health Care Fund | 740,600 | 0.55% | $32.23M | 0.08% | Jul 31, 2026 |
| T. Rowe Price Integrated U.S. Small-Cap Growth Equity Fund | 728,490 | 0.54% | $34.27M | 0.35% | Jun 30, 2026 |
| Janus Henderson Global Life Sciences Fund | 710,241 | 0.53% | $33.41M | 0.58% | Jun 30, 2026 |
| Eventide Healthcare & Life Sciences Fund | 710,000 | 0.53% | $33.40M | 1.87% | Jun 30, 2026 |
| Driehaus Small Cap Growth Fund | 595,284 | 0.44% | $28.00M | 1.74% | Jun 30, 2026 |
| Lord Abbett Developing Growth Fund Inc | 538,017 | 0.40% | $23.41M | 1.05% | Jul 31, 2026 |
Officers, directors and major owners
People who filed Forms 3, 4 or 5 in the last two years
| Name | Role | Shares owned | % of shares | Latest filing |
|---|---|---|---|---|
| Robert Barrow | Chief Executive Officer, Director | 2,213,090 | 1.65% | Sep 29, 2026 |
| Daniel Karlin | Chief Medical Officer, Director | 792,846 | 0.59% | Sep 29, 2026 |
| Mark Sullivan | Chief Legal Officer | 494,228 | 0.37% | Sep 29, 2026 |
| Brandi Roberts | Chief Financial Officer | 394,528 | 0.29% | Sep 29, 2026 |
| Matthew T. Wiley | Chief Commercial Officer | 359,036 | 0.27% | Sep 29, 2026 |
| Carrie Liao | Chief Accounting Officer | 144,923 | 0.11% | Mar 26, 2025 |
| Carol A. Vallone | Director | 22,296 | 0.02% | Sep 18, 2026 |
| Andreas Krebs | Director | 21,402 | 0.02% | Sep 18, 2026 |
| David W. Gryska | Director | 19,900 | 0.01% | Jun 15, 2026 |
| Suzanne Louise Bruhn | Director | 24,289 | 0.02% | Jun 15, 2026 |
| Roger Adsett | Director | 3,555 | 0.00% | Jun 15, 2026 |
| Roger Crystal | Director | 24,289 | 0.02% | Jun 15, 2026 |
Insider trades
Common stock transactions reported on Form 4, newest first
| Insider | Date | Transaction | Shares | Price | Value | Shares after |
|---|---|---|---|---|---|---|
| Matthew T. Wiley Chief Commercial Officer | Sep 25, 2026 | Sale(10b5-1 plan) | −3,097 | $36.57 | $113.26K | 359,036 |
| Brandi Roberts Chief Financial Officer | Sep 25, 2026 | Sale(10b5-1 plan) | −3,377 | $36.57 | $123.50K | 394,528 |
| Mark Sullivan Chief Legal Officer | Sep 25, 2026 | Sale(10b5-1 plan) | −14,051 | $36.57 | $513.85K | 494,228 |
| Daniel Karlin Chief Medical Officer, Director | Sep 25, 2026 | Sale(10b5-1 plan) | −10,853 | $36.57 | $396.89K | 792,846 |
| Robert Barrow Chief Executive Officer, Director | Sep 25, 2026 | Sale(10b5-1 plan) | −31,550 | $36.57 | $1.15M | 2,213,090 |
| Carol A. Vallone Director | Sep 18, 2026 | Option exercise | +1,086 | $35.52 | $38.57K | 22,296 |
| Andreas Krebs Director | Sep 18, 2026 | Option exercise | +1,629 | $35.52 | $57.86K | 21,402 |
| Mark Sullivan Chief Legal Officer | Sep 14, 2026 | Award | +125,000 | – | – | 508,279 |
| Matthew T. Wiley Chief Commercial Officer | Sep 14, 2026 | Award | +125,000 | – | – | 362,133 |
| Daniel Karlin Chief Medical Officer | Sep 14, 2026 | Award | +200,000 | – | – | 803,699 |
| Robert Barrow Chief Executive Officer, Director | Sep 14, 2026 | Award | +750,000 | – | – | 2,244,640 |
| Brandi Roberts Chief Financial Officer | Sep 14, 2026 | Award | +125,000 | – | – | 397,905 |
| Robert Barrow Chief Executive Officer, Director | Sep 3, 2026 | Sale(10b5-1 plan) | −19,023 | $37.94 | $721.73K | 1,494,640 |
| Robert Barrow Chief Executive Officer, Director | Sep 2, 2026 | Award | +40,000 | – | – | 1,513,663 |
| Daniel Karlin Chief Medical Officer | Aug 12, 2026 | Award | +100,000 | – | – | 603,282 |
| Robert Barrow Chief Executive Officer, Director | Aug 12, 2026 | Award | +375,000 | – | – | 1,473,246 |
| Matthew T. Wiley Chief Commercial Officer | Aug 12, 2026 | Award | +62,500 | – | – | 237,133 |
| Mark Sullivan Chief Legal Officer | Aug 12, 2026 | Award | +62,500 | – | – | 383,071 |
| Brandi Roberts Chief Financial Officer | Aug 12, 2026 | Award | +62,500 | – | – | 271,987 |
| Robert Barrow Chief Executive Officer, Director | Jun 25, 2026 | Sale(10b5-1 plan) | −29,208 | $45.03 | $1.32M | 1,098,246 |
| Matthew T. Wiley Chief Commercial Officer | Jun 25, 2026 | Sale(10b5-1 plan) | −2,867 | $45.03 | $129.10K | 174,633 |
| Mark Sullivan Chief Legal Officer | Jun 25, 2026 | Sale(10b5-1 plan) | −13,008 | $45.03 | $585.75K | 320,571 |
| Brandi Roberts Chief Financial Officer | Jun 25, 2026 | Sale(10b5-1 plan) | −3,013 | $45.03 | $135.68K | 209,487 |
| Daniel Karlin Chief Medical Officer | Jun 25, 2026 | Sale(10b5-1 plan) | −10,035 | $45.03 | $451.88K | 503,282 |
| Matthew T. Wiley Chief Commercial Officer | Jun 22, 2026 | Award | +62,500 | – | – | 177,500 |
| Mark Sullivan Chief Legal Officer | Jun 22, 2026 | Award | +62,500 | – | – | 333,579 |
| Daniel Karlin Chief Medical Officer | Jun 22, 2026 | Award | +100,000 | – | – | 513,317 |
| Brandi Roberts Chief Financial Officer | Jun 22, 2026 | Award | +62,500 | – | – | 212,500 |
| Robert Barrow Chief Executive Officer, Director | Jun 22, 2026 | Award | +375,000 | – | – | 1,127,454 |
| Roger Crystal Director | Jun 11, 2026 | Award | +4,666 | – | – | 24,289 |
| Andreas Krebs Director | Jun 11, 2026 | Award | +4,666 | – | – | 19,773 |
| Carol A. Vallone Director | Jun 11, 2026 | Award | +4,666 | – | – | 21,210 |
| Suzanne Louise Bruhn Director | Jun 11, 2026 | Award | +4,666 | – | – | 24,289 |
| David W. Gryska Director | Jun 11, 2026 | Award | +4,666 | – | – | 19,900 |
| Roger Adsett Director | Jun 11, 2026 | Award | +3,555 | – | – | 3,555 |
| Robert Barrow Chief Executive Officer, Director | Mar 25, 2026 | Sale(10b5-1 plan) | −24,431 | $18.47 | $451.24K | 752,454 |
| Daniel Karlin Chief Medical Officer | Mar 25, 2026 | Sale(10b5-1 plan) | −8,018 | $18.47 | $148.09K | 413,317 |
| Mark Sullivan Chief Legal Officer | Mar 25, 2026 | Sale(10b5-1 plan) | −10,702 | $18.47 | $197.67K | 271,079 |
| Robert Barrow Chief Executive Officer, Director | Feb 3, 2026 | Award | +320,000 | – | – | 1,098,477 |
| Daniel Karlin Chief Medical Officer | Feb 3, 2026 | Award | +150,000 | – | – | 575,025 |
| Mark Sullivan Chief Legal Officer | Feb 3, 2026 | Award | +125,000 | – | – | 407,576 |
| Matthew T. Wiley Chief Commercial Officer | Feb 3, 2026 | Award | +115,000 | – | – | 115,000 |
| Brandi Roberts Chief Financial Officer | Feb 3, 2026 | Award | +150,000 | – | – | 150,000 |
| Robert Barrow Chief Executive Officer, Director | Dec 26, 2025 | Sale(10b5-1 plan) | −25,791 | $13.15 | $339.15K | 778,477 |
| Mark Sullivan Chief Legal Officer | Dec 26, 2025 | Sale(10b5-1 plan) | −11,276 | $13.15 | $148.28K | 282,576 |
| Daniel Karlin Chief Medical Officer | Dec 26, 2025 | Sale(10b5-1 plan) | −5,600 | $13.15 | $73.64K | 425,025 |
| Mark Sullivan Chief Legal Officer | Sep 25, 2025 | Sale(10b5-1 plan) | −11,278 | $9.77 | $110.19K | 293,852 |
| Robert Barrow Chief Executive Officer, Director | Sep 25, 2025 | Sale(10b5-1 plan) | −25,797 | $9.77 | $252.04K | 804,268 |
| Daniel Karlin Chief Medical Officer | Sep 25, 2025 | Sale(10b5-1 plan) | −7,704 | $9.77 | $75.27K | 430,625 |
| Mark Sullivan Chief Legal Officer | Jun 25, 2025 | Sale(10b5-1 plan) | −11,491 | $6.80 | $78.14K | 305,130 |
| Daniel Karlin Chief Medical Officer | Jun 25, 2025 | Sale(10b5-1 plan) | −7,848 | $6.80 | $53.37K | 438,329 |
| Robert Barrow Chief Executive Officer, Director | Jun 25, 2025 | Sale(10b5-1 plan) | −26,491 | $6.80 | $180.14K | 830,065 |
| Daniel Karlin Chief Medical Officer | Mar 25, 2025 | Sale(10b5-1 plan) | −6,836 | $6.74 | $46.07K | 446,177 |
| Mark Sullivan Chief Legal Officer | Mar 25, 2025 | Sale(10b5-1 plan) | −6,576 | $6.74 | $44.32K | 316,621 |
| Robert Barrow Chief Executive Officer, Director | Mar 25, 2025 | Sale(10b5-1 plan) | −21,208 | $6.74 | $142.94K | 856,556 |
| Carrie Liao Chief Accounting Officer | Mar 25, 2025 | Sale(10b5-1 plan) | −2,347 | $6.74 | $15.82K | 144,923 |
| Robert Barrow Chief Executive Officer, Director | Mar 12, 2025 | Award | +350,000 | – | – | 877,764 |
| Carrie Liao Chief Accounting Officer | Mar 12, 2025 | Award | +50,000 | – | – | 142,270 |
| Mark Sullivan Chief Legal Officer | Mar 12, 2025 | Award | +150,000 | – | – | 323,197 |
| Daniel Karlin Chief Medical Officer | Mar 12, 2025 | Award | +115,000 | – | – | 453,013 |
Awards, option exercises, tax withholding and gifts are shown alongside open-market buys and sales. Each name links to the filing on SEC EDGAR.
Planned insider sales
Notices of proposed sale filed on Form 144 before shares are sold
| Seller | Filed | Shares | Market value | Planned sale | Acquired through |
|---|---|---|---|---|---|
| Sullivan Mark Officer | Sep 25, 2026 | 14,051 | $516.09K | Sep 25, 2026 | Restricted Stock Vesting Under a Registered Plan |
| Roberts Brandi Officer | Sep 25, 2026 | 3,377 | $124.04K | Sep 25, 2026 | Restricted Stock Vesting Under a Registered Plan |
| Thomas Wiley Matthew Officer | Sep 25, 2026 | 3,097 | $113.75K | Sep 25, 2026 | Restricted Stock Vesting Under a Registered Plan |
| Rollings Karlin Daniel Officer | Sep 25, 2026 | 10,853 | $398.63K | Sep 25, 2026 | Restricted Stock Vesting Under a Registered Plan |
| B. Barrow Robert Officer, Director | Sep 25, 2026 | 31,550 | $1.16M | Sep 25, 2026 | Restricted Stock Vesting Under a Registered Plan |
| B. Barrow Robert Officer, Director | Sep 3, 2026 | 19,023 | $718.14K | Sep 3, 2026 | Performance Stock Units |
| B. Barrow Robert Officer, Director | Jun 25, 2026 | 29,208 | $1.23M | Jun 25, 2026 | Restricted Stock Vesting Under a Registered Plan |
| Rollings Karlin Daniel Officer | Jun 25, 2026 | 10,035 | $422.77K | Jun 25, 2026 | Restricted Stock Vesting Under a Registered Plan |
| Roberts Brandi Officer | Jun 25, 2026 | 3,013 | $126.94K | Jun 25, 2026 | Restricted Stock Vesting Under a Registered Plan |
| Sullivan Mark Officer | Jun 25, 2026 | 13,008 | $548.03K | Jun 25, 2026 | Restricted Stock Vesting Under a Registered Plan |
| Thomas Wiley Matthew Officer | Jun 25, 2026 | 2,867 | $120.79K | Jun 25, 2026 | Restricted Stock Vesting Under a Registered Plan |
| Sullivan Mark Officer | Mar 25, 2026 | 10,702 | $197.67K | Mar 25, 2026 | Restricted stock vesting under a registered plan |
| Rollings Karlin Daniel Officer | Mar 25, 2026 | 8,018 | $148.09K | Mar 25, 2026 | Restricted stock vesting under a registered plan |
| B. Barrow Robert Officer, Director | Mar 25, 2026 | 24,431 | $451.24K | Mar 25, 2026 | Restricted stock vesting under a registered plan |
| Sullivan, Mark Officer | Dec 29, 2025 | 11,276 | $148.24K | Dec 26, 2025 | Restricted Stock Vesting |