Gossamer Bio Inc
Ownership
Ownership Structure
Who owns Gossamer Bio Inc (GOSS)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 62.7% of the shares are freely tradable; institutional investors hold 75.2%.
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| D. E. Shaw & Co LP | 8.38 | 40,959,285 | +10,417.7 | 06/30/2026 |
| Worth Venture Partners, LLC | 5.12 | 25,017,881 | +0.0 | 06/30/2026 |
| Kalehua Capital Management LLC | 3.62 | 17,708,133 | +0.0 | 03/31/2026 |
| BlackRock Inc | 3.44 | 16,826,695 | -1.3 | 03/31/2026 |
| GSA Capital Partners LLP | 3.07 | 14,986,947 | +360.5 | 06/30/2026 |
| AQR Capital Management LLC | 2.07 | 10,126,897 | +804.8 | 03/31/2026 |
| Vanguard Capital Management, LLC | 1.92 | 9,394,593 | +0.0 | 03/31/2026 |
| ARCH VENTURE CORP | 1.65 | 8,055,916 | +0.0 | 06/30/2026 |
| Octagon Capital Advisors LP | 1.59 | 7,750,000 | +0.0 | 06/30/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| Vanguard MStar Total Stk Mkt Idx Invest | 2.96 | 6,910,934 | +0.0 | 07/31/2026 |
Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.
Data as of: September 18, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.