Mustang Bio's three largest insider shareholders as of September 29, 2026 are Biotech, Inc. Fortress (TenPercentOwner, 536.58K shares), Brian Achenbach (Svp, Fin. Corp. Controller, 9.65K shares), Manuel Md Litchman (President, Ceo And Interim Cfo, 1.61K shares).
| # | Insider | Position | Direct | Indirect | Total | Share of Insiders | Last Filed |
|---|---|---|---|---|---|---|---|
| 1 | Biotech, Inc. Fortress | TenPercentOwner | 536,577 | 0 | 536,577 | 97.7% | 05 Jan, 2026 |
| 2 | Brian Achenbach | Svp, Fin. Corp. Controller | 9,649 | 0 | 9,649 | 1.8% | 16 Dec, 2021 |
| 3 | Manuel Md Litchman | President, Ceo And Interim Cfo | 1,874 | 0 | 1,874 | 0.3% | 27 Apr, 2026 |
| 4 | Adam J. Chill | Director | 375 | 0 | 375 | 0.1% | 30 Dec, 2025 |
| 5 | David Jin | Director | 286 | 0 | 286 | 0.1% | 30 Dec, 2025 |
| 6 | Neil Herskowitz | Director | 145 | 0 | 145 | 0.0% | 30 Dec, 2025 |
| 7 | Lindsay A Md Rosenwald | Director | 81 | 0 | 81 | 0.0% | 07 Jul, 2023 |
| 8 | Michael S Weiss | Director | 0 | 66 | 66 | 0.0% | 07 Jul, 2023 |
| 9 | Michael J Zelefsky | Director | 25 | 0 | 25 | 0.0% | 07 Jul, 2023 |
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 |
|---|---|---|---|---|---|---|---|---|
| 24 Apr, 2026 | Manuel Md Litchman | President, Ceo And Interim Cfo | Disposed F | 19 | $0.75 | $14 | 1,615 | Direct |
| 02 Jan, 2026 | Biotech, Inc. Fortress | TenPercentOwner | Acquired A | 278,385 | $0.00 | $0 | 536,577 | Direct |
| 30 Dec, 2025 | Neil Herskowitz | Director | Disposed S | 247 | $0.96 | $238 | 145 | Direct |
| 30 Dec, 2025 | David Jin | Director | Acquired P | 247 | $0.96 | $238 | 286 | Direct |
| 30 Dec, 2025 | Adam J. Chill | Director | Disposed S | 4 | $0.95 | $4 | 375 | Direct |
| 29 Sep, 2025 | Biotech, Inc. Fortress | TenPercentOwner | Acquired A | 59,334 | $0.00 | $0 | 258,192 | Direct |
| 24 Apr, 2025 | Manuel Md Litchman | President, Ceo And Interim Cfo | Disposed F | 27 | $1.24 | $33 | 1,634 | Direct |
| 31 Mar, 2025 | Biotech, Inc. Fortress | TenPercentOwner | Acquired A | 67,806 | $0.00 | $0 | 198,858 | Direct |
| 27 Jun, 2024 | Biotech, Inc. Fortress | TenPercentOwner | Acquired A | 575,191 | $0.00 | $0 | 3,337 | Direct |
| 31 May, 2024 | Manuel Md Litchman | President And Ceo | Disposed F | 1,396 | $262.49 | $366.43K | 111 | Direct |
| 02 Jan, 2024 | Biotech, Inc. Fortress | TenPercentOwner | Acquired A | 419,092 | $0.00 | $0 | 2,571 | Direct |
| 05 Jul, 2023 | Adam J. Chill | Director | Acquired A | 7,246 | $0.00 | $0 | 26 | Direct |
| 05 Jul, 2023 | Neil Herskowitz | Director | Acquired A | 7,246 | $0.00 | $0 | 26 | Direct |
| 05 Jul, 2023 | Lindsay A Md Rosenwald | Director | Acquired A | 7,246 | $0.00 | $0 | 81 | Direct |
| 05 Jul, 2023 | Michael S Weiss | Director | Acquired A | 7,246 | $0.00 | $0 | 66 | Indirect |
| 24 Apr, 2023 | Manuel Md Litchman | President And Ceo | Acquired A | 5,000 | $0.00 | $0 | 148 | Direct |
| 05 Jul, 2023 | Michael J Zelefsky | Director | Acquired A | 7,246 | $0.00 | $0 | 25 | Direct |
| 06 Jan, 2023 | Biotech, Inc. Fortress | TenPercentOwner | Acquired A | 2,807,008 | $0.00 | $0 | 1,508,783 | Direct |
| 08 Dec, 2021 | Brian Achenbach | Svp, Fin. Corp. Controller | Acquired A | 22,500 | $0.00 | $0 | 9,941 | Direct |
| 14 Dec, 2021 | Brian Achenbach | Svp, Fin. Corp. Controller | Disposed S | 4,374 | $27.45 | $120.06K | 9,649 | Direct |