GOSS · Insider Trading
Gossamer Bio, Inc. Common Stock
Every open-market purchase and sale reported by GOSS officers, directors and 10%+ beneficial owners on SEC Form 4, which must be filed within two business days of the transaction. Sales often reflect scheduled 10b5-1 plans or tax withholding rather than a directional view, so read counts alongside the size and the filer.
| Filed | Insider | Role | Type | Shares | Value |
|---|---|---|---|---|---|
| 2026-09-25 | Gregory Austin Ciongoli | Director | A | +30,000 deriv. | — |
| 2026-09-25 | Skye Drynan | Director | A | +10,000 deriv. | — |
| 2026-09-25 | Thomas O Daniel | Director | A | +10,000 deriv. | — |
| 2026-09-25 | Sandra Milligan | Director | A | +10,000 deriv. | — |
| 2026-09-25 | Steven D Nathan | Director | A | +10,000 deriv. | — |
| 2026-09-25 | Russell J. Cox | Director | A | +10,000 deriv. | — |
| 2026-09-25 | John D Quisel | Director | A | +10,000 deriv. | — |
| 2026-08-26 | Robert Paul Smith JR | Chief Commercial Officer | A | +5,800,051 deriv. | — |
| 2026-08-26 | Bryan Giraudo | COO/CFO | A | +5,800,076 deriv. | — |
| 2026-08-26 | Waage Christian | EVP, Tech Ops and Admin | A | +2,900,026 deriv. | — |
| 2026-08-26 | Caryn Peterson | Chief Development Officer | A | +5,800,051 deriv. | — |
| 2026-08-26 | Faheem Hasnain | President & CEO | A | +5,800,217 deriv. | — |
| 2026-06-05 | Steven D Nathan | Director | A | +115,000 deriv. | — |
| 2026-06-05 | Sandra Milligan | Director | A | +115,000 deriv. | — |
| 2026-06-05 | Russell J. Cox | Director | A | +115,000 deriv. | — |
| 2026-06-05 | John D Quisel | Director | A | +115,000 deriv. | — |
| 2026-06-05 | Thomas O Daniel | Director | A | +115,000 deriv. | — |
| 2026-06-05 | Skye Drynan | Director | A | +115,000 deriv. | — |
| 2026-03-20 | Robert Paul Smith JR | Chief Commercial Officer | MIXED | — | — |
| 2026-03-20 | Waage Christian | EVP, Tech Ops and Admin | MIXED | — | — |
| 2026-03-20 | Caryn Peterson | EVP, Regulatory Affairs | MIXED | — | — |
| 2026-03-20 | Richard Aranda | Chief Medical Officer | MIXED | — | — |
| 2026-03-20 | Bryan Giraudo | COO/CFO | MIXED | — | — |
| 2026-03-20 | Faheem Hasnain | President & CEO | MIXED | — | — |
| 2026-01-05 | Caryn Peterson | EVP, Regulatory Affairs | A | +84,500 | — |
| 2026-01-05 | Bryan Giraudo | COO/CFO | A | +115,750 | — |
| 2026-01-05 | Faheem Hasnain | President & CEO | A | +280,000 | — |
| 2026-01-05 | Richard Aranda | Chief Medical Officer | A | +93,750 | — |
| 2026-01-05 | Robert Paul Smith JR | Chief Commercial Officer | A | +93,750 | — |
| 2026-01-05 | Waage Christian | EVP, Tech Ops and Admin | A | +84,500 | — |
| 2025-10-02 | Robert Paul Smith JR | Chief Commercial Officer | A | +162,500 | — |
| 2025-10-02 | Bryan Giraudo | COO/CFO | A | +181,250 | — |
| 2025-10-02 | Faheem Hasnain | President & CEO | A | +437,500 | — |
| 2025-10-02 | Richard Aranda | Chief Medical Officer | A | +162,500 | — |
| 2025-10-02 | Waage Christian | EVP, Tech Ops and Admin | A | +125,000 | — |
| 2025-10-02 | Caryn Peterson | EVP, Regulatory Affairs | A | +125,000 | — |
| 2025-08-20 | Sandra Milligan | Director | Buy | +26,050 | +$50.02K |
| 2025-06-26 | Thomas O Daniel | Director | A | +115,000 deriv. | — |
| 2025-06-26 | Skye Drynan | Director | A | +115,000 deriv. | — |
| 2025-06-26 | Sandra Milligan | Director | A | +115,000 deriv. | — |
| 2025-06-26 | Russell J. Cox | Director | A | +115,000 deriv. | — |
| 2025-06-26 | Steven D Nathan | Director | A | +115,000 deriv. | — |
| 2025-06-26 | John D Quisel | Director | A | +115,000 deriv. | — |
| 2025-03-06 | Richard Aranda | Chief Medical Officer | A | +572,000 deriv. | — |
| 2025-03-06 | Waage Christian | EVP, Tech Ops and Admin | A | +440,000 deriv. | — |
| 2025-03-06 | Caryn Peterson | EVP, Regulatory Affairs | A | +440,000 deriv. | — |
| 2025-03-06 | Bryan Giraudo | COO/CFO | A | +638,000 deriv. | — |
| 2025-03-06 | Robert Paul Smith JR | Chief Commercial Officer | A | +572,000 deriv. | — |
| 2025-03-06 | Faheem Hasnain | President & CEO | A | +1,540,000 deriv. | — |
| 2024-06-25 | Richard Aranda | Chief Medical Officer | Sell | −1,908 | −$1.26K |
| Insider | Role | Shares Held | Value |
|---|---|---|---|
| Faheem Hasnain | President & CEO | 78,073 | $735.45K |
| Bryan Giraudo | COO/CFO | 10,872 | $102.41K |
| Waage Christian | EVP, Tech Ops and Admin | 10,750 | $101.27K |
| Richard Aranda | Chief Medical Officer | 5,821 | $54.83K |
| Robert Paul Smith JR | Chief Commercial Officer | 3,573 | $33.66K |
| Caryn Peterson | Chief Development Officer | 3,242 | $30.54K |
| Sandra Milligan | Director | 1,126 | $10.61K |
| Thomas O Daniel | Director | 476 | $4.48K |
| Russell J. Cox | Director | 90 | $848 |
Form 4 reports a change in beneficial ownership by an officer, director or 10%+ holder, and must be filed within two business days of the transaction — so this is close to real time, unlike the 45-day-lagged 13F institutional data.
Transaction codes matter more than the raw buy/sell count. Code P is an open-market purchase — an insider choosing to buy with their own money, which is the signal most research treats as informative. Code S is a sale, but sales are frequently pre-scheduled under a 10b5-1 plan or cover tax withholding on vesting equity, so a run of sales often says nothing directional. Codes A and M are grants and option exercises rather than open-market decisions.
Full filing history and per-insider positions are on the GOSS quote page; the site-wide leaderboard is on the insider transactions hub.
Market data may be delayed, incomplete, or inaccurate. Not a recommendation to buy, sell, or hold any security. Verify quotes with your broker before trading. See Terms §17.