Definium Therapeutics DFTX Insider Ownership

NASDAQ DFTX
$38.51 +0.51 (+1.34%)
As of: Sep 4, 2026 · 2:21 PM EDT

Insider Holdings by Owner

4.50Mn Shares

Insider Ownership Statistics

as of 30 Sep, 2026
Insider Ownership
0.023%
0% pp QoQ
Shares Held by Insiders
19.62K
filed for Sep 2026
0.00% QoQ
Shares Outstanding
85.89Mn
85,885,516 shares
Direct Holdings
19.62K
Indirect: 0
Net Shares Traded (QoQ)
0
no net change in Sep 2026
Insiders Holding Shares
16
with Form 4 holdings on file

Shares Owned by Insiders

Shares held % of outstanding
Latest
Average ownership
Peak ownership

Shares Purchased/Sold by Insiders

Bought Sold
Latest quarter
Net over range
Buying quarters

Insider Ownership Summary

Quarter ending 30 Sep, 2026

As of August 29, 2026, the three largest insider holders of DFTX are Robert Barrow (Chief Executive Officer, 1.47Mn shares), Robert Barrow (Chief Executive Officer, 752.45K shares), Daniel Karlin (Chief Medical Officer, 603.28K shares).

Form 4 Holdings

Insiders Holding DFTX

Insiders 16
Shares held 4.50Mn
Of outstanding 5.24%
# Insider Position Direct Indirect Total Share of Insiders Last Filed
1 Robert Barrow Chief Executive Officer 1,738,386 0 1,738,386 38.6% 12 Aug, 2026
2 Daniel Karlin Chief Medical Officer 875,144 0 875,144 19.4% 12 Aug, 2026
3 Mark Sullivan Chief Legal Officer 383,071 0 383,071 8.5% 12 Aug, 2026
4 Schond L. Greenway Chief Financial Officer 295,728 0 295,728 6.6% 26 Mar, 2024
5 Wernli Miri Halperin Executive President 287,409 0 287,409 6.4% 22 Aug, 2024
6 Brandi Roberts Chief Financial Officer 271,987 0 271,987 6.0% 12 Aug, 2026
7 Matthew T. Wiley Chief Commercial Officer 237,133 0 237,133 5.3% 12 Aug, 2026
8 Carrie Liao Chief Accounting Officer 171,820 0 171,820 3.8% 26 Mar, 2025
9 Cynthia W. Hu Chief Legal Officersecretary 80,004 0 80,004 1.8% 28 Mar, 2022
10 Carol A Vallone Director 64,314 0 64,314 1.4% 15 Jun, 2026
11 Roger Crystal Director 24,289 0 24,289 0.5% 15 Jun, 2026
12 Andreas Krebs Director 21,210 0 21,210 0.5% 15 Jun, 2026
13 David W Gryska Director 19,900 0 19,900 0.4% 15 Jun, 2026
14 Suzanne Louise Bruhn Director 19,623 0 19,623 0.4% 23 Jun, 2023
15 Brigid Makes Director 10,581 0 10,581 0.2% 06 Jun, 2022
16 Roger Adsett Director 3,555 0 3,555 0.1% 15 Jun, 2026

Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.

Form 4 Filings

247 Insider Transactions

Source SEC Form 4
Latest quarter Sep 2026
Download Data
Date Insider Position Transaction Shares Price Value Shares Held After Ownership
12 Aug, 2026 Robert Barrow Chief Executive Officer Acquired A 375,000 $0.00 $0 1,473,246 Direct
12 Aug, 2026 Mark Sullivan Chief Legal Officer Acquired A 62,500 $0.00 $0 383,071 Direct
12 Aug, 2026 Matthew T. Wiley Chief Commercial Officer Acquired A 62,500 $0.00 $0 237,133 Direct
12 Aug, 2026 Daniel Karlin Chief Medical Officer Acquired A 100,000 $0.00 $0 603,282 Direct
12 Aug, 2026 Brandi Roberts Chief Financial Officer Acquired A 62,500 $0.00 $0 271,987 Direct
25 Jun, 2026 Brandi Roberts Chief Financial Officer Disposed S 3,013 $45.03 $135.68K 209,487 Direct
25 Jun, 2026 Robert Barrow Chief Executive Officer Disposed S 29,208 $45.03 $1.32Mn 1,098,246 Direct
25 Jun, 2026 Mark Sullivan Chief Legal Officer Disposed S 13,008 $45.03 $585.75K 320,571 Direct
25 Jun, 2026 Matthew T. Wiley Chief Commercial Officer Disposed S 2,867 $45.03 $129.10K 174,633 Direct
25 Jun, 2026 Daniel Karlin Chief Medical Officer Disposed S 10,035 $45.03 $451.88K 503,282 Direct
22 Jun, 2026 Brandi Roberts Chief Financial Officer Acquired A 62,500 $0.00 $0 212,500 Direct
22 Jun, 2026 Matthew T. Wiley Chief Commercial Officer Acquired A 62,500 $0.00 $0 177,500 Direct
22 Jun, 2026 Daniel Karlin Chief Medical Officer Acquired A 100,000 $0.00 $0 513,317 Direct
22 Jun, 2026 Robert Barrow Chief Executive Officer Acquired A 375,000 $0.00 $0 1,127,454 Direct
22 Jun, 2026 Mark Sullivan Chief Legal Officer Acquired A 62,500 $0.00 $0 333,579 Direct
11 Jun, 2026 Andreas Krebs Director Acquired A 4,666 $0.00 $0 19,773 Direct
11 Jun, 2026 Carol A Vallone Director Acquired A 4,666 $0.00 $0 21,210 Direct
11 Jun, 2026 Roger Crystal Director Acquired A 4,666 $0.00 $0 24,289 Direct
11 Jun, 2026 Roger Adsett Director Acquired A 3,555 $0.00 $0 3,555 Direct
11 Jun, 2026 David W Gryska Director Acquired A 4,666 $0.00 $0 19,900 Direct