Definium Therapeutics, Inc. (DFTX) Insider Ownership

Historic Insider Ownership Trends

As of May 30, 2026, the three largest insider holders of DFTX are Dan Karlin (Chief Medical Officer, 4.08Mn shares), Robert Barrow (Chief Executive Officer, 3.98Mn shares), Miri Halperin Wernli (Executive President, 1.27Mn shares).

Top Direct Holders

Insider ownership data is derived from the last 60 months of Form 4 SEC filings.
Holder Position Shares (Direct) Shares (Indirect) Report Date
David W Gryska - 19,851 0 05 Dec, 2024
Mark Sullivan Chief Legal Officer 271,079 0 26 Mar, 2026
Cynthia W. Hu Chief Legal Officersecretary 1,200,000 0 28 Mar, 2022
Brigid Makes - 158,706 0 06 Jun, 2022
Carol A Vallone - 43,104 0 06 Jun, 2022
Andreas Krebs - 21,552 0 06 Jun, 2022
Brandi Roberts Chief Financial Officer 150,000 0 05 Feb, 2026
Suzanne Louise Bruhn - 19,623 0 23 Jun, 2023
Roger Crystal - 19,623 0 23 Jun, 2023
Matthew T. Wiley Chief Commercial Officer 115,000 0 05 Feb, 2026
Schond L. Greenway Chief Financial Officer 1,270,000 0 03 Jun, 2022
Robert Barrow Chief Executive Officer 3,976,894 0 26 May, 2022
Miri Halperin Wernli Executive President 1,275,000 0 28 Mar, 2022
Dan Karlin Chief Medical Officer 4,077,719 0 31 May, 2022
Carrie Liao Vp, Controlleracct Principal 403,430 0 14 Mar, 2022

* Please note that the shares above only reflect shares from the fund portfolio and the institutional portfolio. Shares from the personal portfolio are excluded from this Institutional Ownership Page. See these insiders' latest transactions here on Insider Page.

Recent Insider Transactions

Detailed insider trading activity based on Form 4 SEC filings.
Download Data
Transaction Date Insider Name Security Class Transaction Type Shares Traded Price Shares Remaining Ownership Code
25 Mar, 2026 Mark Sullivan Common Shares D 10,702 $18.47 271,079 D S
25 Mar, 2026 Mark Sullivan Common Shares D 10,702 $18.47 271,079 D S
25 Mar, 2026 Robert Barrow Common Shares D 24,431 $18.47 752,454 D S
25 Mar, 2026 Daniel Karlin Common Shares D 8,018 $18.47 413,317 D S
03 Feb, 2026 Mark Sullivan Common Shares A 125,000 $0.00 407,576 D A
03 Feb, 2026 Brandi Roberts Common Shares A 150,000 $0.00 150,000 D A
03 Feb, 2026 Matthew T. Wiley Common Shares A 115,000 $0.00 115,000 D A
03 Feb, 2026 Matthew T. Wiley Common Shares A 115,000 $0.00 115,000 D A
03 Feb, 2026 Robert Barrow Common Shares A 320,000 $0.00 1,098,477 D A
03 Feb, 2026 Mark Sullivan Common Shares A 125,000 $0.00 407,576 D A
03 Feb, 2026 Daniel Karlin Common Shares A 150,000 $0.00 575,025 D A
29 Jan, 2026 Roger Adsett Stock Option (Right to Buy) A 50,000 $0.00 50,000 D A
26 Dec, 2025 Mark Sullivan Common Shares D 11,276 $13.15 282,576 D S
26 Dec, 2025 Mark Sullivan Common Shares D 11,276 $13.15 282,576 D S
26 Dec, 2025 Daniel Karlin Common Shares D 5,600 $13.15 425,025 D S
26 Dec, 2025 Robert Barrow Common Shares D 25,791 $13.15 778,477 D S
25 Sep, 2025 Daniel Karlin Common Shares D 7,704 $9.77 430,625 D S
25 Sep, 2025 Mark Sullivan Common Shares D 11,278 $9.77 293,852 D S
25 Sep, 2025 Robert Barrow Common Shares D 25,797 $9.77 804,268 D S
25 Sep, 2025 Mark Sullivan Common Shares D 11,278 $9.77 293,852 D S