X4 Pharmaceuticals's top three insider shareholders as of September 05, 2026 are Adam R Craig (Executive Chairman, 328.65K shares), John Volpone (President, 289.88K shares), David Kirske (Chief Financial Officer, 167.75K shares).
| # | Insider | Position | Direct | Indirect | Total | Share of Insiders | Last Filed |
|---|---|---|---|---|---|---|---|
| 1 | Adam R Craig | Executive Chairman | 328,651 | 0 | 328,651 | 36.8% | 13 Aug, 2026 |
| 2 | John Volpone | President | 289,881 | 0 | 289,881 | 32.4% | 14 Aug, 2025 |
| 3 | David Kirske | Chief Financial Officer | 167,750 | 0 | 167,750 | 18.8% | 01 Jul, 2026 |
| 4 | Mark Baldry | Chief Commercial Officer | 25,337 | 0 | 25,337 | 2.8% | 03 Jun, 2025 |
| 5 | Paula Ragan | President And Ceo | 18,540 | 0 | 18,540 | 2.1% | 14 Feb, 2025 |
| 6 | Natasha Fay Thoren | Chief Legal Officer | 9,462 | 0 | 9,462 | 1.1% | 03 Jul, 2025 |
| 7 | Murray Stewart | Interim Chief Medical Officer | 7,883 | 0 | 7,883 | 0.9% | 10 Jun, 2025 |
| 8 | Mary Dibiase | Chief Operating Officer | 6,338 | 0 | 6,338 | 0.7% | 14 Feb, 2025 |
| 9 | Keith Woods | Director | 6,000 | 0 | 6,000 | 0.7% | 10 Jun, 2025 |
| 10 | Michael S Wyzga | Director | 5,555 | 0 | 5,555 | 0.6% | 10 Jun, 2025 |
| 11 | Christophe Arbet-Engels | Chief Medical Officer | 4,801 | 0 | 4,801 | 0.5% | 14 Feb, 2025 |
| 12 | David W J Mcgirr | Director | 4,722 | 0 | 4,722 | 0.5% | 10 Jun, 2025 |
| 13 | Gary Bridger | Director | 4,722 | 0 | 4,722 | 0.5% | 10 Jun, 2025 |
| 14 | Craecker Francoise De | Director | 4,722 | 0 | 4,722 | 0.5% | 10 Jun, 2025 |
| 15 | Adam S. Mostafa | Chief Financial Officer | 4,722 | 0 | 4,722 | 0.5% | 14 Feb, 2025 |
| 16 | Arthur Taveras | Chief Scientific Officer | 2,156 | 0 | 2,156 | 0.2% | 08 Oct, 2024 |
| 17 | Derek M Meisner | Chief Legal Officer | 806 | 0 | 806 | 0.1% | 19 Aug, 2022 |
| 18 | Diego Cadavid | Chief Medical Officer | 578 | 0 | 578 | 0.1% | 01 Mar, 2022 |
| 19 | Alison Frances Lawton | Director | 537 | 0 | 537 | 0.1% | 11 Jun, 2024 |
| 20 | William Aliski | Director | 537 | 0 | 537 | 0.1% | 11 Jun, 2024 |
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.
| Date | Insider | Position | Transaction | Shares | Price | Value | Shares Held After | Ownership |
|---|---|---|---|---|---|---|---|---|
| 12 Aug, 2026 | Adam R Craig | Executive Chairman | Disposed S | 47,436 | $4.44 | $210.83K | 328,651 | Direct |
| 01 Jul, 2026 | Kelly Gold | Director | Acquired A | 110,000 | $0.00 | $0 | 110,000 | Direct |
| 30 Jun, 2026 | David Kirske | Chief Financial Officer | Disposed S | 8,543 | $4.26 | $36.43K | 167,750 | Direct |
| 12 May, 2026 | David Kirske | Chief Financial Officer | Disposed S | 16,961 | $4.29 | $72.82K | 176,293 | Direct |
| 01 Jan, 2026 | Gary Bridger | Director | Acquired A | 110,000 | $0.00 | $0 | 0 | Direct |
| 01 Jan, 2026 | Craecker Francoise De | Director | Acquired A | 110,000 | $0.00 | $0 | 0 | Direct |
| 01 Jan, 2026 | Craecker Francoise De | Director | Acquired A | 110,000 | $0.00 | $0 | 0 | Direct |
| 01 Jan, 2026 | Michael S Wyzga | Director | Acquired A | 110,000 | $0.00 | $0 | 0 | Direct |
| 01 Jan, 2026 | Murray Stewart | Director | Acquired A | 110,000 | $0.00 | $0 | 0 | Direct |
| 01 Jan, 2026 | Craecker Francoise De | Director | Acquired A | 110,000 | $0.00 | $0 | 0 | Direct |
| 01 Jan, 2026 | Craecker Francoise De | Director | Acquired A | 110,000 | $0.00 | $0 | 0 | Direct |
| 29 Oct, 2025 | Adam R Craig | Executive Chairman | Acquired A | 2,329,154 | $0.00 | $0 | 2,329,154 | Direct |
| 29 Oct, 2025 | John Volpone | President | Acquired A | 2,329,154 | $0.00 | $0 | 2,329,154 | Direct |
| 29 Oct, 2025 | David Kirske | Chief Financial Officer | Acquired A | 1,552,769 | $0.00 | $0 | 1,552,769 | Direct |
| 23 Oct, 2025 | Adam R Craig | Executive Chairman | Acquired P | 86,206 | $2.90 | $250.00K | 376,087 | Direct |
| 14 Aug, 2025 | David Kirske | Chief Financial Officer | Acquired A | 193,254 | $0.00 | $0 | 193,254 | Direct |
| 14 Aug, 2025 | John Volpone | President | Acquired A | 289,881 | $0.00 | $0 | 289,881 | Direct |
| 14 Aug, 2025 | Adam R Craig | Executive Chairman | Acquired A | 289,881 | $0.00 | $0 | 289,881 | Direct |
| 12 Aug, 2025 | Adam R Craig | Executive Chairman | Acquired A | 1,609,873 | $0.00 | $0 | 1,609,873 | Direct |
| 12 Aug, 2025 | John Volpone | President | Acquired A | 1,609,873 | $0.00 | $0 | 1,609,873 | Direct |