As of March 23, 2026, the three largest insider holders of MRKR are John Robert Wilson (Director, 7.81Mn shares), Juan Vera (Chief Scientific Officer Coo, 2.67Mn shares), Enterprise Associates 16, L.P. New (TenPercentOwner, 1.63Mn shares).
| Holder | Position | Shares (Direct) | Shares (Indirect) | Report Date |
|---|---|---|---|---|
| John Robert Wilson | 7,812,008 | 0 | 10 Jun, 2021 | |
| Juan Vera | Chief Scientific Officer Coo | 2,671,845 | 0 | 28 Mar, 2022 |
| Enterprise Associates 16, L.P. New | 1,625,678 | 0 | 23 Dec, 2024 | |
| Enterprise Associates 16, L.P. New | 1,625,678 | 0 | 23 Dec, 2024 | |
| Peter L. Hoang | President And Ceo | 483,286 | 0 | 28 Mar, 2022 |
| Steve Elms | 0 | 325,370 | 26 Dec, 2024 | |
| Anthony H. Kim | Chief Financial Officer | 114,436 | 0 | 28 Mar, 2022 |
| Frederick Gerald Wasserman | 65,223 | 0 | 10 Jun, 2021 | |
| David Laskow-Pooley | 55,223 | 0 | 10 Jun, 2021 | |
| Norman David Eansor | 36,940 | 0 | 10 Jun, 2021 | |
| Steve Elms | 29,680 | 0 | 10 Jun, 2021 |
* 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.
| Transaction Date | Insider Name | Security Class | Transaction Type | Shares Traded | Price | Shares Remaining | Ownership | Code |
|---|---|---|---|---|---|---|---|---|
| 17 Nov, 2025 | Katharine Knobil | Stock Option (Right to Buy) | A | 84,411 | $0.00 | 84,411 | D | A |
| 17 Nov, 2025 | Norman David Eansor | Stock Option (Right to Buy) | A | 84,411 | $0.00 | 84,411 | D | A |
| 17 Nov, 2025 | Steve Elms | Stock Option (right to buy) | A | 84,411 | $0.00 | 84,411 | D | A |
| 17 Nov, 2025 | Norman David Eansor | Stock Option (Right to Buy) | A | 137,330 | $0.00 | 137,330 | D | A |
| 17 Nov, 2025 | Katharine Knobil | Stock Option (Right to Buy) | A | 137,330 | $0.00 | 137,330 | D | A |
| 17 Nov, 2025 | Steve Elms | Stock Option (right to buy) | A | 137,330 | $0.00 | 137,330 | D | A |
| 31 Oct, 2025 | Juan Vera | Employee Stock Option (right to buy) | A | 250,000 | $0.00 | 250,000 | D | A |
| 31 Oct, 2025 | Kathryn Penkus Corzo | Stock Option (Right to Buy) | A | 147,611 | $0.00 | 147,611 | D | A |
| 12 Feb, 2025 | Norman David Eansor | Stock Option (right to buy) | A | 30,000 | $0.00 | 30,000 | D | A |
| 12 Feb, 2025 | Katharine Knobil | Stock Option (right to buy) | A | 30,000 | $0.00 | 30,000 | D | A |
| 12 Feb, 2025 | Juan Vera | Employee Stock Option (right to buy) | A | 50,000 | $0.00 | 50,000 | D | A |
| 12 Feb, 2025 | Steve Elms | Stock Option (right to buy) | A | 30,000 | $0.00 | 30,000 | D | A |
| 23 Dec, 2024 | Steve Elms | Common Stock | A | 11,085 | $3.20 | 325,370 | I | P |
| 23 Dec, 2024 | Enterprise Associates 16, L.P. New | Common Stock | A | 554,250 | $3.20 | 1,625,678 | D | P |
| 23 Dec, 2024 | Enterprise Associates 16, L.P. New | Common Stock | A | 554,250 | $3.20 | 1,625,678 | D | P |
| 06 Jun, 2023 | Katharine Knobil | Stock Option (right to buy) | A | 8,000 | $0.00 | 8,000 | D | A |
| 06 Jun, 2023 | Steve Elms | Stock Option (right to buy) | A | 8,000 | $0.00 | 8,000 | D | A |
| 06 Jun, 2023 | John Robert Wilson | Stock Option (right to buy) | A | 8,000 | $0.00 | 8,000 | D | A |
| 10 May, 2023 | Juan Vera | Employee Stock Option (right to buy) | A | 100,000 | $0.00 | 100,000 | D | A |
| 27 Feb, 2023 | Anna Szymanska | Employee Stock Option (right to buy) | A | 29,947 | $0.00 | 29,947 | D | A |