X4 Pharmaceuticals's three largest insider shareholders as of March 23, 2026 are Paula Ragan (President And Ceo, 3.34Mn shares), Mary Dibiase (Chief Operating Officer, 1.14Mn shares), Christophe Arbet-Engels (Chief Medical Officer, 864.21K shares).
| Holder | Position | Shares (Direct) | Shares (Indirect) | Report Date |
|---|---|---|---|---|
| Paula Ragan | President And Ceo | 3,337,386 | 0 | 14 Feb, 2025 |
| Mary Dibiase | Chief Operating Officer | 1,140,980 | 0 | 14 Feb, 2025 |
| Christophe Arbet-Engels | Chief Medical Officer | 864,207 | 0 | 14 Feb, 2025 |
| Adam S. Mostafa | Chief Financial Officer | 850,000 | 0 | 14 Feb, 2025 |
| Arthur Taveras | Chief Scientific Officer | 388,026 | 0 | 08 Oct, 2024 |
| Adam R Craig | Executive Chairman | 376,087 | 0 | 27 Oct, 2025 |
| John Volpone | President | 289,881 | 0 | 14 Aug, 2025 |
| David Kirske | Chief Financial Officer | 193,254 | 0 | 14 Aug, 2025 |
| Derek M Meisner | Chief Legal Officer | 145,155 | 0 | 19 Aug, 2022 |
| Diego Cadavid | Chief Medical Officer | 104,107 | 0 | 01 Mar, 2022 |
| Alison Frances Lawton | 96,667 | 0 | 11 Jun, 2024 | |
| William Aliski | 96,667 | 0 | 11 Jun, 2024 | |
| Mark Baldry | Chief Commercial Officer | 25,337 | 0 | 03 Jun, 2025 |
| Natasha Fay Thoren | Chief Legal Officer | 9,462 | 0 | 03 Jul, 2025 |
| Murray Stewart | 7,883 | 0 | 10 Jun, 2025 | |
| Keith Woods | 6,000 | 0 | 10 Jun, 2025 | |
| Gary Bridger | 4,722 | 0 | 10 Jun, 2025 | |
| Craecker Francoise De | 4,722 | 0 | 10 Jun, 2025 |
* 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 |
|---|---|---|---|---|---|---|---|---|
| 01 Jan, 2026 | Gary Bridger | Stock Option (right to buy) | A | 110,000 | $0.00 | 0 | D | A |
| 01 Jan, 2026 | Murray Stewart | Stock Option (right to buy) | A | 110,000 | $0.00 | 0 | D | A |
| 01 Jan, 2026 | Craecker Francoise De | Stock Option (right to buy) | A | 110,000 | $0.00 | 0 | D | A |
| 29 Oct, 2025 | John Volpone | Stock Option (right to buy) | A | 2,329,154 | $0.00 | 2,329,154 | D | A |
| 29 Oct, 2025 | David Kirske | Stock Option (right to buy) | A | 1,552,769 | $0.00 | 1,552,769 | D | A |
| 29 Oct, 2025 | Adam R Craig | Stock Option (right to buy) | A | 2,329,154 | $0.00 | 2,329,154 | D | A |
| 23 Oct, 2025 | Adam R Craig | Common Stock | A | 86,206 | $2.90 | 376,087 | D | P |
| 14 Aug, 2025 | David Kirske | Common Stock | A | 193,254 | $0.00 | 193,254 | D | A |
| 14 Aug, 2025 | Adam R Craig | Common Stock | A | 289,881 | $0.00 | 289,881 | D | A |
| 14 Aug, 2025 | John Volpone | Common Stock | A | 289,881 | $0.00 | 289,881 | D | A |
| 12 Aug, 2025 | Adam R Craig | Stock Option (right to buy) | A | 1,609,873 | $0.00 | 1,609,873 | D | A |
| 12 Aug, 2025 | John Volpone | Stock Option (right to buy) | A | 1,609,873 | $0.00 | 1,609,873 | D | A |
| 12 Aug, 2025 | David Kirske | Stock Option (right to buy) | A | 1,073,249 | $0.00 | 1,073,249 | D | A |
| 14 Aug, 2025 | David Kirske | Stock Option (right to buy) | A | 352,800 | $0.00 | 352,800 | D | A |
| 14 Aug, 2025 | Adam R Craig | Stock Option (right to buy) | A | 529,201 | $0.00 | 529,201 | D | A |
| 14 Aug, 2025 | John Volpone | Stock Option (right to buy) | A | 529,201 | $0.00 | 529,201 | D | A |
| 20 May, 2025 | Natasha Fay Thoren | Common Stock | A | 3,333 | $0.00 | 9,462 | D | A |
| 09 Jun, 2025 | Craecker Francoise De | Common Stock | A | 1,500 | $0.00 | 4,722 | D | A |
| 09 Jun, 2025 | Keith Woods | Common Stock | A | 1,500 | $0.00 | 6,000 | D | A |
| 09 Jun, 2025 | Murray Stewart | Common Stock | A | 1,500 | $0.00 | 7,883 | D | A |