Gossamer Bio, Inc.
Gossamer Bio, Inc. (GOSS) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · GOSS · as of Mar 31, 2025
Ownership Breakdown
126
Institutional Holders
▲ 11 vs Q4
$186.89M
Total Inst. Value
▲ $31.85M vs Q4
234.70M
Shares Outstanding
freeFloat 83.14%
169.98M
13F Shares Held
▼ 1.39M vs Q4
Institutional ownership = 13F shares ÷ total outstanding. Insider % = 100 − free float. Public % = free float − institution %. Data: FMP /symbol-positions-summary + /shares-float + SEC EDGAR.
Top Institutional Holders
GOSS largest shareholders · institutional ownership
Q1 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
OCTAGON CAPITAL ADVISORS LP pharmaceutical preparations | 18.35M | 8.09% | 8.09% | $20.18B | May 16, 2025 | — held |
NEA MANAGEMENT COMPANY, LLC pharmaceutical preparations | 18.09M | 8.00% | 8.00% | $19.90B | May 14, 2025 | — held |
VANGUARD GROUP INC pharmaceutical preparations | 10.08M | 4.45% | 4.45% | $11.09B | May 9, 2025 | ▲ 49.7K |
ARCH VENTURE MANAGEMENT, LLC pharmaceutical preparations | 8.06M | 3.56% | 3.56% | $8.78B | May 15, 2025 | — held |
FMR LLC pharmaceutical preparations | 7.59M | 3.35% | 3.35% | $8.35B | May 12, 2025 | ▼ 340.0K |
ACADIAN ASSET MANAGEMENT LLC pharmaceutical preparations | 6.36M | 2.80% | 2.80% | $6.99B | May 21, 2025 | ▲ 1.25M |
SILVERARC CAPITAL MANAGEMENT, LLC pharmaceutical preparations | 6.32M | 2.79% | 2.79% | $6.95B | May 14, 2025 | ▲ 148.8K |
PALO ALTO INVESTORS LP pharmaceutical preparations | 6.28M | 2.77% | 2.77% | $6.90B | May 15, 2025 | ▼ 200 |
SAMSARA BIOCAPITAL, LLC pharmaceutical preparations | 6.13M | 2.71% | 2.71% | $6.74B | May 15, 2025 | — held |
683 CAPITAL MANAGEMENT, LLC pharmaceutical preparations | 6.10M | 2.69% | 2.69% | $6.71B | May 15, 2025 | ▼ 875.0K |
Data from SEC Form 13F filings. Ownership bar normalised to largest holder. Change flags: isNew / isSoldOut / changeInSharesNumber (FMP extract-analytics/holder).
Institutional Activity
Q1 2025 vs prior quarter
Q1 2025
18
Increased
+8.17M shares4
New Positions
first time holders16
Decreased
−11.86M shares0
Sold Out
fully exitedNet shares change (top 50)
3.69M
+8.17M / −11.86M
Net new holders
+6
4 new / 0 exited
Based on top 50 institutional holders by position size. Fields: isNew, isSoldOut, changeInSharesNumber (FMP extract-analytics/holder, limit=50).
Insider Buying vs Selling
GOSS insider trading · insider activity
Source: SEC Form 4
6
Buy transactions
0
Sell transactions
0.00
Buy/Sell ratio
$0M
Total disposed
Recent Insider Transactions
Showing 10 most recent · Common Stock only
| Name · Role | Date | Type | Shares | Price | Value | After Trans. | Filing |
|---|---|---|---|---|---|---|---|
Quisel John D director | Jun 4, 2026 | Award | 115,000 | $0.18 | $20.5K | 115.0K | Form 4 ↗ |
Drynan Skye director | Jun 4, 2026 | Award | 115,000 | $0.18 | $20.5K | 115.0K | Form 4 ↗ |
Daniel Thomas O director | Jun 4, 2026 | Award | 115,000 | $0.18 | $20.5K | 115.0K | Form 4 ↗ |
Cox Russell J. director | Jun 4, 2026 | Award | 115,000 | $0.18 | $20.5K | 115.0K | Form 4 ↗ |
Milligan Sandra director | Jun 4, 2026 | Award | 115,000 | $0.18 | $20.5K | 115.0K | Form 4 ↗ |
Nathan Steven D director | Jun 4, 2026 | Award | 115,000 | $0.18 | $20.5K | 115.0K | Form 4 ↗ |
Aranda Richard Chief Medical Officer | Mar 19, 2026 | Award | 572,000 | $0.45 | $257.4K | 572.0K | Form 4 ↗ |
Aranda Richard Chief Medical Officer | Mar 19, 2026 | Award | 562,500 | $0.45 | $253.1K | 562.5K | Form 4 ↗ |
Aranda Richard Chief Medical Officer | Mar 19, 2026 | Award | 487,500 | $0.45 | $219.4K | 487.5K | Form 4 ↗ |
Aranda Richard Chief Medical Officer | Mar 19, 2026 | Award | 162,500 | $0.45 | $73.1K | 162.5K | Form 4 ↗ |
Source: /insider-trading/search (FMP stable). Buy/Sell direction: acquisitionOrDisposition A=Buy, D=Sell. RSU vesting (M-Exempt) excluded from sentiment bar. All data from SEC EDGAR public filings.
About institutional & insider ownership
Gossamer Bio, Inc. (GOSS) is primarily owned by institutional investors, who hold approximately 72.4% of total shares outstanding. Company insiders own approximately 16.86%, while retail and public investors account for the remaining 10.71%.
The largest institutional shareholder of Gossamer Bio, Inc. is OCTAGON CAPITAL ADVISORS LP, holding approximately 18.35 million shares — equal to 8.09% of outstanding shares — as of March 31, 2025.
A total of 126 institutional investors currently hold GOSS stock, with a combined institutional value of approximately $186,890,454 as of the most recent 13F filing period.
Frequently asked questions
GOSS ownershipGossamer Bio, Inc. (GOSS) is primarily owned by institutional investors, who hold approximately 72.4% of shares. The largest shareholder is OCTAGON CAPITAL ADVISORS LP with a 8.09% stake. Company insiders hold 16.86%. Data sourced from SEC Form 13F as of March 31, 2025.