According to recent filings covering the 90 days ending February 07, 2026, the three most significant insider holders at Gossamer Bio are President & Ceo Faheem Hasnain (6.25Mn shares), Coo/Cfo Bryan Giraudo (869.75K shares), Evp And Tech Ops And Admin Waage Christian (859.95K shares).
| Holder | Position | Shares | Report Date |
|---|---|---|---|
| Faheem Hasnain | President & Ceo | 6,245,866 | 05 Jan, 2026 |
| Bryan Giraudo | Coo/Cfo | 869,747 | 05 Jan, 2026 |
| Waage Christian | Evp And Tech Ops And Admin | 859,953 | 05 Jan, 2026 |
| Richard Aranda | Chief Medical Officer | 463,106 | 05 Jan, 2026 |
| Robert Paul Jr Smith | Chief Commercial Officer | 285,898 | 05 Jan, 2026 |
| Caryn Peterson | Evp And Regulatory Affairs | 259,333 | 05 Jan, 2026 |
| Sandra Milligan | 90,050 | 20 Aug, 2025 | |
| Laura Carter | Chief Scientific Officer | 76,263 | 20 Mar, 2023 |
* 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 |
|---|---|---|---|---|---|---|---|---|
| 02 Jan, 2026 | Faheem Hasnain | Common Stock | A | 280,000 | $0.00 | 837,793 | D | A |
| 02 Jan, 2026 | Waage Christian | Common Stock | A | 84,500 | $0.00 | 814,061 | D | A |
| 02 Jan, 2026 | Bryan Giraudo | Common Stock | A | 115,750 | $0.00 | 389,737 | D | A |
| 02 Jan, 2026 | Caryn Peterson | Common Stock | A | 84,500 | $0.00 | 259,333 | D | A |
| 02 Jan, 2026 | Richard Aranda | Common Stock | A | 93,750 | $0.00 | 463,106 | D | A |
| 02 Jan, 2026 | Robert Paul Jr Smith | Common Stock | A | 93,750 | $0.00 | 260,898 | D | A |
| 01 Oct, 2025 | Faheem Hasnain | Common Stock | A | 437,500 | $0.00 | 557,793 | D | A |
| 01 Oct, 2025 | Waage Christian | Common Stock | A | 125,000 | $0.00 | 710,934 | D | A |
| 01 Oct, 2025 | Bryan Giraudo | Common Stock | A | 181,250 | $0.00 | 273,987 | D | A |
| 01 Oct, 2025 | Caryn Peterson | Common Stock | A | 125,000 | $0.00 | 174,833 | D | A |
| 01 Oct, 2025 | Richard Aranda | Common Stock | A | 162,500 | $0.00 | 369,356 | D | A |
| 01 Oct, 2025 | Robert Paul Jr Smith | Common Stock | A | 162,500 | $0.00 | 162,500 | D | A |
| 19 Aug, 2025 | Sandra Milligan | - | - | 58,050 | D | |||
| 19 Aug, 2025 | Sandra Milligan | Common Stock | A | 26,050 | $1.92 | 58,050 | D | P |
| 24 Jun, 2024 | Richard Aranda | - | - | 196,891 | D | |||
| 24 Jun, 2024 | Richard Aranda | Common Stock | D | 1,908 | $0.66 | 196,891 | D | S |
| 21 Jun, 2024 | Faheem Hasnain | - | - | 5,408,073 | I | |||
| 21 Jun, 2024 | Faheem Hasnain | Common Stock | A | 372,000 | $0.67 | 5,408,073 | I | P |
| 18 Jun, 2024 | Bryan Giraudo | - | - | 480,010 | I | |||
| 18 Jun, 2024 | Bryan Giraudo | Common Stock | A | 100,000 | $0.59 | 480,010 | I | P |