Comparable stake leader
683 Capital Management, LLC
SEC ownership of Gossamer Bio, Inc.
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001728117.
Disclosed value leader
683 Capital Management, LLC
Comparable rows
50/50
Latest evidence
20 Aug 2026
- Public ticker
- GOSS on Nasdaq
- Parsed ownership sources
-
13D/G and 13F
Source: Parsed SEC ownership filingsUse: Compare filing families carefully
- Largest SEC-reported holder
-
683 Capital Management, LLC
Ranking: Comparable ownership first, then disclosed value
- Comparable ownership rows
-
50 of 50
Meaning: Rows with safely comparable ownership %
- Latest 13D/G holder
-
683 Capital Management, LLC
Source: Latest parsed Schedule 13D/G stake
- Latest parsed ownership date
-
20 Aug 2026
Freshness: Most recent filing date in this holder set
- Issuer CIK
- 0001728117
- Issuer location
- San Diego, CA
Ownership snapshot
CIK-linked ownership evidence from parsed SEC filings.
3 signals
Issuer
Names, identifiers, and filing context for this profile.
2 identity fields
Ownership snapshot
Top shareholders of Gossamer Bio, Inc. (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
683 Capital Management, LLC
Disclosed value leader
683 Capital Management, LLC
Comparable rows
50/50
Latest evidence
20 Aug 2026
13D/G
13F
Lead comparable stake: 10%
13D/G row: 683 Capital Management, LLC
Showing 1-8 of 50 holder rows.
Quick read
683 Capital Management, LLC leads the comparable SEC ownership view at 10%.
50 of 50 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens 683 Capital Management, LLC's linked filing trail.
Comparable ownership
Top 5
683 Capital Management, LLC
10%
Context Capital Management, LLC
9.9%
DeepCurrents Investment Group LLC
7.7%
D. E. SHAW & CO, L.P.
6%
Opaleye Management Inc.
5.1%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-8 of 50 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| 683 Capital Management, LLC |
13D/G
13F
Company
|
10%
|
$16,955,314
49,868,571 shares
|
+$13,782,671 | 04 Jun 2026 |
| Context Capital Management, LLC |
13D/G
13F
Company
|
9.9%
|
$16,604,168
48,835,788 shares
|
$0 | 04 Jun 2026 |
| DeepCurrents Investment Group LLC |
13D/G
13F
Company
|
7.7%
|
$12,806,125
37,665,073 shares
|
$0 | 04 Jun 2026 |
| D. E. SHAW & CO, L.P. |
13D/G
D. E. Shaw & Co., L.L.C.
|
6%
|
$5,243,075
29,128,194 shares
|
-$986,647 | 20 Aug 2026 |
| Opaleye Management Inc. |
13D/G
|
5.1%
|
$4,105,546
24,942,565 shares
|
$0 | 22 Jul 2026 |
| Octagon Capital Advisors LP |
13D/G
13F
Company
|
3.8%
|
$3,590,422
8,976,054 shares
|
-$2,466,148 | 31 Mar 2026 |
| Invus Global Management, LLC |
13D/G
Invus Public Equities, L.P.
|
2.8%
|
$5,507,814
6,258,880 shares
|
$0 | 31 Dec 2024 |
| Growth Equity Opportunities 18 VGE, LLC |
13D/G
|
1.7%
|
$10,366,092
4,065,134 shares
|
$0 | 23 Feb 2026 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Insider trading overview
Insider buy and sell flow is broadly balanced over the last 12 months. No Buy or Sell transactions have been reported since 05 Sep 2025.
Buys
$0
Insiders: 0
Sells
$0
Insiders: 0
Net
$0
Shares: 0
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 0
Shares: 0
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 0 | 0 | $0 | $0 | $0 |
| 3-6 | 0 | 0 | $0 | $0 | $0 |
| 6-9 | 0 | 0 | $0 | $0 | $0 |
| 9-12 | 0 | 0 | $0 | $0 | $0 |
Reporting owners
Insider holders from Forms 3/4/5
Showing 1-16 of 16 reporting-owner rows connected to Gossamer Bio, Inc.. Open a relationship link for the CIK-to-CIK filing trail.
Rows
16
Largest Forms 3/4/5 holder
Faheem Hasnain
Net 12M change
$0
Latest report
24 Aug 2026
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| Faheem Hasnain | President & CEO, Director | $22,610,034 | Mixed | 24 Aug 2026 | ||
| Waage Christian | EVP, Tech Ops and Admin | $3,193,472 | Mixed | 24 Aug 2026 | ||
| Bryan Giraudo | Coo/Cfo | $3,148,483 | Mixed | 24 Aug 2026 | ||
| Richard Aranda | Chief Medical Officer | $1,685,634 | Mixed | 19 Mar 2026 | ||
| Robert Paul Smith Jr. | Chief Commercial Officer | $1,034,950 | Mixed | 24 Aug 2026 | ||
| Caryn Peterson | Chief Development Officer | $938,785 | Mixed | 24 Aug 2026 | ||
| Sandra Milligan | Director | $111,456 | Filing P/S | 04 Jun 2026 | ||
| Laura Carter | Chief Scientific Officer | $60,088 | Mixed | 20 Mar 2023 | ||
| Russell J. Cox | Director | Mixed | 04 Jun 2026 | |||
| Skye Drynan | Director | Mixed | 04 Jun 2026 | |||
| Renee D. Gala | Director | Mixed | 08 Jun 2023 | |||
| Daniel Thomas O | Director | Mixed | 04 Jun 2026 | |||
| John D. Quisel | Director | Mixed | 04 Jun 2026 | |||
| Kristina Burow | Director | Mixed | 08 Jun 2023 | |||
| Steven D. Nathan | Director | Mixed | 04 Jun 2026 | |||
| Joshua H. Bilenker | Director | Mixed | 09 Jun 2022 |
Recent insider transactions for Gossamer Bio, Inc.
Showing up to 300 recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | SEC-reported value | SEC-reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Waage Christian | GOSS | Stock Option (Right to Buy) | Award | 2,900,026 | 2,900,026 | 24 Aug 2026 | Direct | |||
| Caryn Peterson | GOSS | Stock Option (Right to Buy) | Award | 5,800,051 | 5,800,051 | 24 Aug 2026 | Direct | |||
| Robert Paul Smith Jr. | GOSS | Stock Option (Right to Buy) | Award | 5,800,051 | 5,800,051 | 24 Aug 2026 | Direct | |||
| Bryan Giraudo | GOSS | Stock Option (Right to Buy) | Award | 5,800,051 | 5,800,051 | 24 Aug 2026 | Direct | |||
| Bryan Giraudo | GOSS | Pre-Funded Warrant (Right to Buy) | Award | 25 | 25 | 24 Aug 2026 | By Family Trust | |||
| Faheem Hasnain | GOSS | Stock Option (Right to Buy) | Award | 5,800,051 | 5,800,051 | 24 Aug 2026 | Direct | |||
| Faheem Hasnain | GOSS | Pre-Funded Warrant (Right to Buy) | Award | 166 | 166 | 24 Aug 2026 | By Family Trust | |||
| John D. Quisel | GOSS | Stock Option (Right to Buy) | Award | 115,000 | 115,000 | 04 Jun 2026 | Direct | |||
| Skye Drynan | GOSS | Stock Option (Right to Buy) | Award | 115,000 | 115,000 | 04 Jun 2026 | Direct | |||
| Daniel Thomas O | GOSS | Stock Option (Right to Buy) | Award | 115,000 | 115,000 | 04 Jun 2026 | Direct | |||
| Russell J. Cox | GOSS | Stock Option (Right to Buy) | Award | 115,000 | 115,000 | 04 Jun 2026 | Direct | |||
| Sandra Milligan | GOSS | Stock Option (Right to Buy) | Award | 115,000 | 115,000 | 04 Jun 2026 | Direct | |||
| Steven D. Nathan | GOSS | Stock Option (Right to Buy) | Award | 115,000 | 115,000 | 04 Jun 2026 | Direct | |||
| Richard Aranda | GOSS | Stock Option (Right to Buy) | Award | 2,348,118 | 572,000 | 19 Mar 2026 | Direct | |||
| Richard Aranda | GOSS | Stock Option (Right to Buy) | Disposed to Issuer | -100% | -2,348,118 | 0 | 19 Mar 2026 | Direct | ||
| Caryn Peterson | GOSS | Stock Option (Right to Buy) | Award | 1,992,203 | 506,250 | 19 Mar 2026 | Direct | |||
| Caryn Peterson | GOSS | Stock Option (Right to Buy) | Disposed to Issuer | -100% | -1,992,203 | 0 | 19 Mar 2026 | Direct | ||
| Robert Paul Smith Jr. | GOSS | Stock Option (Right to Buy) | Award | 1,134,500 | 572,000 | 19 Mar 2026 | Direct | |||
| Robert Paul Smith Jr. | GOSS | Stock Option (Right to Buy) | Disposed to Issuer | -100% | -1,134,500 | 0 | 19 Mar 2026 | Direct | ||
| Faheem Hasnain | GOSS | Stock Option (Right to Buy) | Award | 7,124,500 | 1,680,000 | 19 Mar 2026 | Direct | |||
| Faheem Hasnain | GOSS | Stock Option (Right to Buy) | Disposed to Issuer | -100% | -7,124,500 | 0 | 19 Mar 2026 | Direct | ||
| Bryan Giraudo | GOSS | Stock Option (Right to Buy) | Award | 2,960,751 | 693,750 | 19 Mar 2026 | Direct | |||
| Bryan Giraudo | GOSS | Stock Option (Right to Buy) | Disposed to Issuer | -100% | -2,960,751 | 0 | 19 Mar 2026 | Direct | ||
| Waage Christian | GOSS | Stock Option (Right to Buy) | Award | 2,065,584 | 506,250 | 19 Mar 2026 | Direct | |||
| Waage Christian | GOSS | Stock Option (Right to Buy) | Disposed to Issuer | -100% | -2,065,584 | 0 | 19 Mar 2026 | Direct | ||
| Faheem Hasnain | GOSS | Common Stock | Award | 50.2% | 280,000 | 837,793 | 02 Jan 2026 | Direct | ||
| Faheem Hasnain | GOSS | Stock Option (Right to Buy) | Award | 1,680,000 | 1,680,000 | 02 Jan 2026 | Direct | |||
| Bryan Giraudo | GOSS | Common Stock | Award | 42.2% | 115,750 | 389,737 | 02 Jan 2026 | Direct | ||
| Bryan Giraudo | GOSS | Stock Option (Right to Buy) | Award | 693,750 | 693,750 | 02 Jan 2026 | Direct | |||
| Robert Paul Smith Jr. | GOSS | Common Stock | Award | 56.1% | 93,750 | 260,898 | 02 Jan 2026 | Direct | ||
| Robert Paul Smith Jr. | GOSS | Stock Option (Right to Buy) | Award | 562,500 | 562,500 | 02 Jan 2026 | Direct | |||
| Richard Aranda | GOSS | Common Stock | Award | 25.4% | 93,750 | 463,106 | 02 Jan 2026 | Direct | ||
| Richard Aranda | GOSS | Stock Option (Right to Buy) | Award | 562,500 | 562,500 | 02 Jan 2026 | Direct | |||
| Caryn Peterson | GOSS | Common Stock | Award | 48.3% | 84,500 | 259,333 | 02 Jan 2026 | Direct | ||
| Caryn Peterson | GOSS | Stock Option (Right to Buy) | Award | 506,250 | 506,250 | 02 Jan 2026 | Direct | |||
| Waage Christian | GOSS | Common Stock | Award | 11.6% | 84,500 | 814,061 | 02 Jan 2026 | Direct | ||
| Waage Christian | GOSS | Stock Option (Right to Buy) | Award | 506,250 | 506,250 | 02 Jan 2026 | Direct | |||
| Robert Paul Smith Jr. | GOSS | Common Stock | Award | 162,500 | 162,500 | 01 Oct 2025 | Direct | |||
| Waage Christian | GOSS | Common Stock | Award | 21.3% | 125,000 | 710,934 | 01 Oct 2025 | Direct | ||
| Bryan Giraudo | GOSS | Common Stock | Award | 195.4% | 181,250 | 273,987 | 01 Oct 2025 | Direct | ||
| Richard Aranda | GOSS | Common Stock | Award | 78.6% | 162,500 | 369,356 | 01 Oct 2025 | Direct | ||
| Faheem Hasnain | GOSS | Common Stock | Award | 363.7% | 437,500 | 557,793 | 01 Oct 2025 | Direct | ||
| Caryn Peterson | GOSS | Common Stock | Award | 250.8% | 125,000 | 174,833 | 01 Oct 2025 | Direct |
* marks a reported price that did not pass the local price check.