As of November 10, 2026, 5 holders' latest Schedule 13D or 13G filings report owning 5% or more of Gossamer Bio, Inc. The largest reported stake is Fmr LLC's, at 10.9%. 23 filings are on record since July 17, 2025 (Schedule 13G, November 6, 2026).
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Key facts
- · Reporting person: Fmr LLC · Sole voting: 667,460 · Shared voting: 0 · Sole dispositive: 667,465 · Shared dispositive: 0 · SCHEDULE 13G, 2026-11-06
- · Reporting person: Opaleye Management Inc. · Sole voting: 0 · Shared voting: 426,989 · Sole dispositive: 0 · Shared dispositive: 426,989 · SCHEDULE 13G/A, 2026-11-06
- · Reporting person: D. E. Shaw Valence Portfolios, L.L.C. · Sole voting: 0 · Shared voting: 243,041 · Sole dispositive: 0 · Shared dispositive: 243,041 · SCHEDULE 13D/A, 2026-10-29
- · Holder: D. E. Shaw & Co., L.P. · Percent: 6% · SCHEDULE 13D/A
- · Holder: D. E. Shaw & Co., L.P. · Percent: 5.1% · SCHEDULE 13D/A
Gossamer Bio, Inc. has 23 Schedule 13D or 13G filings on record since 2025-07-17. 5 holders' latest filing reports 5% or more of common stock, par value $0.0001 per share. Each figure below is the holder's own, as filed, with the filing linked.
Holders
| Holder | Percent | Shares | Latest | Event date |
|---|---|---|---|---|
| Fmr LLC | 10.9% | 667,465 | SCHEDULE 13G, 2026-11-06 | 2026-10-30 |
| 683 Capital Management, LLC | 9.99% | 49,868,571 | SCHEDULE 13G, 2026-06-11 | 2026-06-04 |
| Context Capital Management, LLC | 9.9% | 48,835,788 | SCHEDULE 13G, 2026-06-09 | 2026-06-04 |
| DeepCurrents Investment Group LLC | 7.7% | 37,665,073 | SCHEDULE 13G, 2026-06-11 | 2026-06-04 |
| Opaleye Management Inc. | 6.98% | 426,989 | SCHEDULE 13G/A, 2026-11-06 | 2026-09-30 |
| D. E. Shaw & Co., L.P. | 4.2% | 255,431 | SCHEDULE 13D/A, 2026-10-29 | 2026-10-27 |
| Octagon Capital Advisors LP | 3.8% | 8,976,054 | SCHEDULE 13G/A, 2026-05-14 | 2026-03-31 |
| Growth Equity Opportunities 18 VGE, LLC | 1.7% | 4,065,134 | SCHEDULE 13D/A, 2026-02-24 | 2026-02-23 |
| BlackRock, Inc. | 1% | 4,890,593 | SCHEDULE 13G/A, 2026-07-29 | 2026-06-30 |
| The Vanguard Group | 0% | 0 | SCHEDULE 13G/A, 2026-03-27 | 2026-03-13 |
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More on Gossamer Bio, Inc. and the records around it.
Gossamer Bio, Inc. elsewhere on the record
- Leadership changes Sep 2026
- Company profile and every filing Sep 2026
- Form D filing Sep 2026
- Who owns it
Companies that share a holder
- Growth Equity Opportunities 18 VGE, LLC also filed stake reports on 2 other companies: Celcuity Inc. (Mar 2026), X4 Pharmaceuticals, Inc. (Oct 2025)
- Context Capital Management, LLC also filed stake reports on 8 other companies: BOA Acquisition Corp. II (Aug 2026), Cartesian Growth Corp II (Aug 2026), Plum Acquisition Corp, IV (Jul 2026)
- Octagon Capital Advisors LP also filed stake reports on 8 other companies: Precision BioSciences, Inc. (Nov 2026), Context Therapeutics Inc. (Jul 2026), Corbus Pharmaceuticals Holdings, Inc. (May 2026)
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Voting and dispositive power, as filed
| Reporting person | Sole voting | Shared voting | Sole dispositive | Shared dispositive | Filing |
|---|---|---|---|---|---|
| Fmr LLC | 667,460 | 0 | 667,465 | 0 | SCHEDULE 13G, 2026-11-06 |
| Abigail P. Johnson | 0 | 0 | 667,465 | 0 | SCHEDULE 13G, 2026-11-06 |
| 683 Capital Management, LLC | 0 | 49,868,571 | 0 | 49,868,571 | SCHEDULE 13G, 2026-06-11 |
| 683 Capital Partners, LP | 0 | 49,868,571 | 0 | 49,868,571 | SCHEDULE 13G, 2026-06-11 |
| Ari Zweiman | 0 | 49,868,571 | 0 | 49,868,571 | SCHEDULE 13G, 2026-06-11 |
| Context Capital Management, LLC | 0 | 48,835,788 | 0 | 48,835,788 | SCHEDULE 13G, 2026-06-09 |
| Michael S. Rosen | 0 | 48,835,788 | 0 | 48,835,788 | SCHEDULE 13G, 2026-06-09 |
| William D. Fertig | 0 | 48,835,788 | 0 | 48,835,788 | SCHEDULE 13G, 2026-06-09 |
| Charles E. Carnegie | 0 | 48,835,788 | 0 | 48,835,788 | SCHEDULE 13G, 2026-06-09 |
| Context Partners Master Fund, L.P. | 0 | 48,835,788 | 0 | 48,835,788 | SCHEDULE 13G, 2026-06-09 |
| DeepCurrents Investment Group LLC | 0 | 27,646,139 | 0 | 37,665,073 | SCHEDULE 13G, 2026-06-11 |
| Dcig Gp LLC | 0 | 27,646,139 | 0 | 27,646,139 | SCHEDULE 13G, 2026-06-11 |
| DCIG Capital Master Fund LP | 0 | 27,646,139 | 0 | 27,646,139 | SCHEDULE 13G, 2026-06-11 |
| Kai Zheng | 0 | 27,646,139 | 0 | 37,665,073 | SCHEDULE 13G, 2026-06-11 |
| Opaleye Management Inc. | 0 | 426,989 | 0 | 426,989 | SCHEDULE 13G/A, 2026-11-06 |
| Opaleye, L.P. | 0 | 415,000 | 0 | 415,000 | SCHEDULE 13G/A, 2026-11-06 |
| James Silverman | 0 | 426,989 | 0 | 426,989 | SCHEDULE 13G/A, 2026-11-06 |
| D. E. Shaw Valence Portfolios, L.L.C. | 0 | 243,041 | 0 | 243,041 | SCHEDULE 13D/A, 2026-10-29 |
| D. E. Shaw & Co., L.L.C. | 0 | 255,431 | 0 | 255,431 | SCHEDULE 13D/A, 2026-10-29 |
| D. E. Shaw & Co., L.P. | 0 | 255,431 | 0 | 255,431 | SCHEDULE 13D/A, 2026-10-29 |
| David E. Shaw | 0 | 255,431 | 0 | 255,431 | SCHEDULE 13D/A, 2026-10-29 |
| BlackRock, Inc. | 4,890,593 | 0 | 4,890,593 | 0 | SCHEDULE 13G/A, 2026-07-29 |
The latest filing identifies Gossamer Bio, Inc. by CUSIP 38341P201 and gives its principal executive office as 3115 MERRYFIELD ROW, SUITE 120, SAN DIEGO, CA 92121 (SCHEDULE 13G, 2026-11-06).
What the percentages are based on
See items 5-9 and 11 of the cover page for each reporting person. The shares beneficially owned by the Reporting Persons reported in this Schedule 13G consists of 48,835,788 shares held by the Reporting Persons.Context Capital Management, LLC, SCHEDULE 13G, 2026-06-09
Purpose of Transaction (Item 4)
Growth Equity Opportunities 18 VGE, LLC
On February 23, 2026, GEO completed open market sales as part of a series of public sales whereby GEO sold in the aggregate 17,093,034 shares of Common stock at a weighted average price of $0.3906 per share, with prices that ranged from $0.3320 to $0.6363 per share. GEO undertakes to provide to the staff of the Securities and Exchange Commission (the "SEC"), upon request, full information regarding the number of shares sold at each separate price within the range set forth in the previous sentence.Item 4 of the SCHEDULE 13D/A filed 2026-02-24
Timeline
| Filed | Holder | Percent | Filing |
|---|---|---|---|
| 2025-07-17 | BlackRock, Inc. | 5.3% | SCHEDULE 13G |
| 2025-07-29 | The Vanguard Group | 5.02% | SCHEDULE 13G |
| 2026-01-21 | BlackRock, Inc. | 6.5% | SCHEDULE 13G/A |
| 2026-02-17 | Octagon Capital Advisors LP | 6.5% | SCHEDULE 13G/A |
| 2026-02-24 | Growth Equity Opportunities 18 VGE, LLC | 1.7% | SCHEDULE 13D/A |
| 2026-03-02 | 683 Capital Management, LLC | 5.23% | SCHEDULE 13G |
| 2026-03-24 | 683 Capital Management, LLC | 3.9% | SCHEDULE 13G/A |
| 2026-03-27 | The Vanguard Group | 0% | SCHEDULE 13G/A |
| 2026-05-14 | Octagon Capital Advisors LP | 3.8% | SCHEDULE 13G/A |
| 2026-06-09 | Context Capital Management, LLC | 9.9% | SCHEDULE 13G |
| 2026-06-11 | DeepCurrents Investment Group LLC | 7.7% | SCHEDULE 13G |
| 2026-06-11 | D. E. Shaw & Co., L.P. | 9.5% | SCHEDULE 13D |
| 2026-06-11 | 683 Capital Management, LLC | 9.99% | SCHEDULE 13G |
| 2026-07-01 | D. E. Shaw & Co., L.P. | 8.3% | SCHEDULE 13D/A |
| 2026-07-24 | D. E. Shaw & Co., L.P. | 7.1% | SCHEDULE 13D/A |
| 2026-07-29 | Opaleye Management Inc. | 5.1% | SCHEDULE 13G |
| 2026-07-29 | BlackRock, Inc. | 1% | SCHEDULE 13G/A |
| 2026-08-24 | D. E. Shaw & Co., L.P. | 6% | SCHEDULE 13D/A |
| 2026-09-28 | D. E. Shaw & Co., L.P. | 5.1% | SCHEDULE 13D/A |
| 2026-10-08 | D. E. Shaw & Co., L.P. | 6% | SCHEDULE 13D/A |
| 2026-10-29 | D. E. Shaw & Co., L.P. | 4.2% | SCHEDULE 13D/A |
| 2026-11-06 | Fmr LLC | 10.9% | SCHEDULE 13G |
| 2026-11-06 | Opaleye Management Inc. | 6.98% | SCHEDULE 13G/A |
Questions about who owns Gossamer Bio, Inc.
Who owns Gossamer Bio, Inc.?
On this page, 5 holders' latest ownership filings report 5% or more of Gossamer Bio, Inc.: Fmr LLC (10.9%, Schedule 13G, filed 2026-11-06), 683 Capital Management, LLC (9.99%, Schedule 13G, filed 2026-06-11), Context Capital Management, LLC (9.9%, Schedule 13G, filed 2026-06-09), DeepCurrents Investment Group LLC (7.7%, Schedule 13G, filed 2026-06-11) and Opaleye Management Inc. (6.98%, Schedule 13G/A, filed 2026-11-06).
Who are the largest shareholders of Gossamer Bio, Inc.?
By the share each holder's latest filing reports, the largest holders of Gossamer Bio, Inc. on this page are Fmr LLC (10.9%), 683 Capital Management, LLC (9.99%) and Context Capital Management, LLC (9.9%).
When did Fmr LLC buy into Gossamer Bio, Inc.?
The filings give report dates, not purchase dates. The earliest filing from Fmr LLC on this page is the Schedule 13G, filed 2026-11-06, reporting 10.9%.
Is this an audit or a full list?
Neither. The ownership list on this page covers only Schedule 13D and 13G filings, which holders make once they own 5% or more of a class of shares (an amendment can report a stake that has since fallen below 5%); 23 such filings are shown here. It is not an audit and not a full cap table: holders who never reached 5% are not listed, and a stake can change after its latest filing.
Also on the record for Gossamer Bio, Inc.
| Date | Record | Figure | Our page | Source |
|---|---|---|---|---|
| September 16, 2026 | Leadership change: Gregory A. Ciongoli appointed, Director, and 1 more | — | Leadership changes | Source |
| September 4, 2026 | Form D, private offering | $25M sold | Form D page | Source |
| June 19, 2026 | Court case: Sparks v. Gossamer Bio, Inc., District Court, S.D. California | — | Court records | Source |
| March 31, 2026 | Court case: Kinnamon v. Gossamer Bio, Inc., District Court, S.D. California | — | Court records | Source |
| April 3, 2020 | Court case: Kuhne v. Gossamer Bio, Inc., District Court, S.D. California | — | Court records | Source |
Gossamer Bio, Inc.: every filing and event
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Where this comes from
Anyone who comes to own more than 5% of a class of a listed company's voting shares has to tell the SEC. A holder who may seek to change or influence the company files Schedule 13D, and has to say in Item 4, "Purpose of Transaction", what it intends to do. A holder with no such intent, such as many index and passive funds, may file the shorter Schedule 13G. Both are amended when the stake changes, including when it falls below 5%.
Every row here is one of those filings, linked to the filing itself. Percentages and share counts are exactly as the holder filed them, for the holder the filing names; an amendment showing a lower figure is shown as filed. Item 4 text is quoted word for word. Where a 13D's Item 4 contains a sentence stating a definite intent to influence the company, that sentence is marked and quoted; the page does not describe the holder or its motives beyond the words it filed. Nothing here is investment advice.