Who owns Gossamer Bio, Inc. (GOSS)
Which tracked institutional funds hold GOSS, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See GOSS company fundamentals →
Ownership as of the 2026-Q1 13F filings (latest filed 2026-05-18). 13F is disclosed up to 45 days after quarter-end, so the most recent quarter fills in over the following weeks.
How the tape is positioned
The tracked-fund tape on GOSS is one-sided between 2025-Q4 and 2026-Q1: 6 added or opened and 75 trimmed or exited — on balance reducing.
A prompt to read the filings, not a verdict. 13F is a quarter-end snapshot disclosed up to 45 days late; a fund adds or exits for mandate, benchmark, and timing reasons that have nothing to do with a view on the stock. This is a starting question, not a signal to trade.
Conviction spread
GOSS’s largest tracked holder by dollar value, VANGUARD GROUP INC, sizes it at 0.0% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 0.0pp gap the other way — the median holder sizes GOSS more heavily than its largest holder by dollar value does.
Book-share is each fund’s reported value in GOSS divided by its whole reported 13F book, so it is comparable across funds of different sizes and is unaffected by stock splits. A higher share means a fund has committed more of its book to the name — a starting question about conviction, not a verdict or a signal to trade.
Institutional & insider positioning
Between 2025-Q4 and 2026-Q1, across 183 tracked filers holding GOSS, 116 increased or opened the position and 106 reduced or closed it; over the same quarter, there were no open-market insider Form 4s.
This fuses two public signals for the same quarter — how tracked institutions changed their positions and whether insiders bought or sold in the open market. It describes what was filed; it is a starting question, not a verdict or a signal to trade.
New buyers & exits
Funds opening or closing a position in GOSS between the 2025-Q4 and 2026-Q1 13F filings, and the largest changes among funds holding it in both. New buyers and exits are counted on fund presence (split-invariant); adds and trims are measured on reported value.
New buyers 4
- VANGUARD CAPITAL MANAGEMENT LLC$3M
- Kalehua Capital Management LLC$2M
- VANGUARD PORTFOLIO MANAGEMENT LLC$711K
- Ensign Peak Advisors, Inc$559K
Full exits 22
- VANGUARD GROUP INC$35M
- Palo Alto Investors LP$14M
- PERCEPTIVE ADVISORS LLC$10M
- Opaleye Management Inc.$8M
- TWO SIGMA ADVISERS, LP$8M
- SILVERARC CAPITAL MANAGEMENT, LLC$7M
Largest adds
- GSA CAPITAL PARTNERS LLP$908K
- Squarepoint Ops LLC$430K
Largest trims
- NEA Management Company, LLC$56M
- BlackRock, Inc.$47M
- Octagon Capital Advisors LP$41M
- STATE STREET CORP$27M
- ARCH Venture Management, LLC$22M
- SAMSARA BIOCAPITAL, LLC$20M
Institutional holders
One row per tracked fund, largest reported value first. “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding. Rows marked stale are from an earlier filing than the security’s latest quarter — that fund is absent from the newest snapshot (position exited, or reported under a different name).
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| BlackRock, Inc. trimmed | 16,826,695 | $6M | 3.0% | 2026-Q1 |
| AQR CAPITAL MANAGEMENT LLC added | 10,038,462 | $3M | 1.8% | 2026-Q1 |
| VANGUARD CAPITAL MANAGEMENT LLC new | 9,394,593 | $3M | 1.7% | 2026-Q1 |
| ARCH Venture Management, LLC | 8,055,916 | $3M | 1.4% | 2026-Q1 |
| Octagon Capital Advisors LP trimmed | 7,750,000 | $3M | 1.4% | 2026-Q1 |
| Kalehua Capital Management LLC new | 7,471,840 | $2M | 1.3% | 2026-Q1 |
| SAMSARA BIOCAPITAL, LLC | 7,222,559 | $2M | 1.3% | 2026-Q1 |
| BALYASNY ASSET MANAGEMENT L.P. added | 5,922,298 | $2M | 1.1% | 2026-Q1 |
| ACADIAN ASSET MANAGEMENT LLC added | 5,277,904 | $2M | 0.9% | 2026-Q1 |
| Siren, L.L.C. | 5,208,968 | $2M | 0.9% | 2026-Q1 |
| 683 Capital Management, LLC trimmed | 5,000,000 | $2M | 0.9% | 2026-Q1 |
| HHLR ADVISORS, LTD. | 4,974,041 | $2M | 0.9% | 2026-Q1 |
| GEODE CAPITAL MANAGEMENT, LLC added | 4,939,691 | $2M | 0.9% | 2026-Q1 |
| Qube Research & Technologies Ltd added | 4,917,763 | $2M | 0.9% | 2026-Q1 |
| TWO SIGMA INVESTMENTS, LP added | 4,780,851 | $2M | 0.9% | 2026-Q1 |
| STATE STREET CORP trimmed | 4,388,109 | $1M | 0.8% | 2026-Q1 |
| Corient Private Wealth LLC added | 3,985,383 | $1M | 0.7% | 2026-Q1 |
| Squarepoint Ops LLC added | 3,398,757 | $1M | 0.6% | 2026-Q1 |
| GSA CAPITAL PARTNERS LLP added | 3,254,233 | $1M | 0.6% | 2026-Q1 |
| BANK OF AMERICA CORP /DE/ added | 3,173,725 | $1M | 0.6% | 2026-Q1 |
| BARCLAYS PLC added | 3,065,806 | $1M | 0.5% | 2026-Q1 |
| Monashee Investment Management LLC added | 2,167,000 | $845K | 0.5% | 2026-Q1 |
| VANGUARD PORTFOLIO MANAGEMENT LLC new | 2,161,079 | $711K | 0.4% | 2026-Q1 |
| Alyeska Investment Group, L.P. added | 2,051,442 | $674K | 0.4% | 2026-Q1 |
| UBS Group AG added | 1,883,583 | $620K | 0.3% | 2026-Q1 |
| ALLIANCEBERNSTEIN L.P. | 190,220 | $590K | 0.3% | 2026-Q1 |
| Ensign Peak Advisors, Inc added | 1,702,125 | $559K | 0.3% | 2026-Q1 |
| JACOBS LEVY EQUITY MANAGEMENT, INC trimmed | 1,695,159 | $557K | 0.3% | 2026-Q1 |
| Rock Springs Capital Management LP trimmed | 1,609,492 | $529K | 0.3% | 2026-Q1 |
| MACKENZIE FINANCIAL CORP added | 1,536,923 | $505K | 0.3% | 2026-Q1 |
| MB Generational Wealth, LLC trimmed | 1,532,142 | $503K | 0.3% | 2026-Q1 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC trimmed | 1,510,076 | $496K | 0.3% | 2026-Q1 |
| NORTHERN TRUST CORP trimmed | 1,408,960 | $463K | 0.3% | 2026-Q1 |
| VANGUARD FIDUCIARY TRUST CO new | 1,404,285 | $462K | 0.3% | 2026-Q1 |
| DEUTSCHE BANK AG\ added | 1,305,886 | $431K | 0.2% | 2026-Q1 |
| RENAISSANCE TECHNOLOGIES LLC added | 1,217,868 | $400K | 0.2% | 2026-Q1 |
| GOLDMAN SACHS GROUP INC trimmed | 1,180,544 | $388K | 0.2% | 2026-Q1 |
| NEA Management Company, LLC trimmed | 1,000,000 | $328K | 0.2% | 2026-Q1 |
| VOYA INVESTMENT MANAGEMENT LLC added | 866,615 | $285K | 0.2% | 2026-Q1 |
| Hennion & Walsh Asset Management, Inc. added | 828,719 | $272K | 0.1% | 2026-Q1 |
| Ishara Investments LP new | 820,000 | $269K | 0.1% | 2026-Q1 |
| XTX Topco Ltd added | 679,125 | $223K | 0.1% | 2026-Q1 |
| Connor, Clark & Lunn Investment Management Ltd. added | 658,221 | $216K | 0.1% | 2026-Q1 |
| SMITH, MOORE & CO. added | 470,000 | $154K | 0.1% | 2026-Q1 |
| PANAGORA ASSET MANAGEMENT INC added | 469,946 | $154K | 0.1% | 2026-Q1 |
| Invesco Ltd. trimmed | 464,968 | $153K | 0.1% | 2026-Q1 |
| VANGUARD GROUP INC trimmed | 11,355,076 | $35M | 19.2% | 2025-Q4 stale |
| Palo Alto Investors LP trimmed | 4,471,592 | $14M | 7.5% | 2025-Q4 stale |
| PERCEPTIVE ADVISORS LLC trimmed | 3,139,669 | $10M | 5.3% | 2025-Q4 stale |
| Opaleye Management Inc. trimmed | 2,720,000 | $8M | 4.6% | 2025-Q4 stale |
| TWO SIGMA ADVISERS, LP added | 2,596,900 | $8M | 4.4% | 2025-Q4 stale |
| SILVERARC CAPITAL MANAGEMENT, LLC trimmed | 2,135,722 | $7M | 3.6% | 2025-Q4 stale |
| Walleye Capital LLC added | 1,077,032 | $3M | 1.8% | 2025-Q4 stale |
| Integral Health Asset Management, LLC added | 1,000,000 | $3M | 1.7% | 2025-Q4 stale |
| HRT FINANCIAL LP added | 956,879 | $3M | 1.6% | 2025-Q4 stale |
| Eversept Partners, LP trimmed | 925,233 | $2M | 1.3% | 2025-Q3 stale |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP added | 750,308 | $2M | 1.3% | 2025-Q4 stale |
| CITADEL ADVISORS LLC trimmed | 704,787 | $2M | 1.2% | 2025-Q4 stale |
| TANG CAPITAL MANAGEMENT LLC trimmed | 800,000 | $2M | 1.1% | 2025-Q3 stale |
| ADAGE CAPITAL PARTNERS GP, L.L.C. added | 726,800 | $2M | 1.0% | 2025-Q3 stale |
| MARSHALL WACE, LLP trimmed | 1,713,655 | $2M | 1.0% | 2025-Q1 stale |
| WELLINGTON MANAGEMENT GROUP LLP trimmed | 601,323 | $2M | 1.0% | 2025-Q4 stale |
| PLATINUM INVESTMENT MANAGEMENT LTD trimmed | 561,951 | $2M | 0.9% | 2025-Q4 stale |
| Laurion Capital Management LP trimmed | 1,343,772 | $2M | 0.9% | 2025-Q2 stale |
| SILVERBACK ASSET MANAGEMENT LLC | 500,000 | $2M | 0.8% | 2025-Q4 stale |
| Exome Asset Management LLC | 451,699 | $1M | 0.8% | 2025-Q4 stale |
| Woodline Partners LP | 495,153 | $1M | 0.7% | 2025-Q3 stale |
| Schonfeld Strategic Advisors LLC added | 897,388 | $1M | 0.6% | 2025-Q2 stale |
| DAFNA Capital Management LLC trimmed | 849,921 | $1M | 0.6% | 2025-Q2 stale |
| ALGERT GLOBAL LLC added | 332,336 | $1M | 0.6% | 2025-Q4 stale |
| Rafferty Asset Management, LLC trimmed | 312,804 | $970K | 0.5% | 2025-Q4 stale |
| Monaco Asset Management SAM trimmed | 309,211 | $959K | 0.5% | 2025-Q4 stale |
| Informed Momentum Co LLC | 278,422 | $863K | 0.5% | 2025-Q4 stale |
| Jain Global LLC trimmed | 278,189 | $862K | 0.5% | 2025-Q4 stale |
| ABSOLUTE INVESTMENT ADVISERS, LLC trimmed | 1,500,000 | $776K | 0.4% | 2025-Q2 stale |
| Allostery Investments LP | 613,028 | $674K | 0.4% | 2025-Q1 stale |
| Atom Investors LP added | 205,639 | $637K | 0.3% | 2025-Q4 stale |
| Stonepine Capital Management, LLC | 204,770 | $635K | 0.3% | 2025-Q4 stale |
| HIGHBRIDGE CAPITAL MANAGEMENT LLC | 497,694 | $612K | 0.3% | 2025-Q2 stale |
| AMERIPRISE FINANCIAL INC added | 434,049 | $534K | 0.3% | 2025-Q2 stale |
| JANE STREET GROUP, LLC trimmed | 155,591 | $482K | 0.3% | 2025-Q4 stale |
| Opti Capital Management, LP added | 414,152 | $456K | 0.2% | 2025-Q1 stale |
| Cubist Systematic Strategies, LLC trimmed | 162,785 | $428K | 0.2% | 2025-Q3 stale |
| PRELUDE CAPITAL MANAGEMENT, LLC | 136,200 | $422K | 0.2% | 2025-Q4 stale |
| Brevan Howard Capital Management LP added | 127,299 | $395K | 0.2% | 2025-Q4 stale |
| Point72 Asset Management, L.P. added | 125,000 | $388K | 0.2% | 2025-Q4 stale |
| PROFUND ADVISORS LLC new | 116,503 | $361K | 0.2% | 2025-Q4 stale |
| Susquehanna Portfolio Strategies, LLC added | 111,350 | $345K | 0.2% | 2025-Q4 stale |
| EntryPoint Capital, LLC added | 105,085 | $326K | 0.2% | 2025-Q4 stale |
| HB Wealth Management, LLC added | 95,924 | $297K | 0.2% | 2025-Q4 stale |
| DIADEMA PARTNERS LP added | 269,589 | $297K | 0.2% | 2025-Q1 stale |
| Lighthouse Investment Partners, LLC new | 92,500 | $287K | 0.2% | 2025-Q4 stale |
| MetLife Investment Management, LLC trimmed | 85,645 | $266K | 0.1% | 2025-Q4 stale |
| ALPS ADVISORS INC trimmed | 99,155 | $261K | 0.1% | 2025-Q3 stale |
| VARCOV Co. new | 83,868 | $260K | 0.1% | 2025-Q4 stale |
| Quadrature Capital Ltd trimmed | 79,709 | $209K | 0.1% | 2025-Q3 stale |
| Voleon Capital Management LP added | 60,235 | $187K | 0.1% | 2025-Q4 stale |
| LAZARD ASSET MANAGEMENT LLC added | 56,668 | $176K | 0.1% | 2025-Q4 stale |
| Engineers Gate Manager LP trimmed | 51,129 | $158K | 0.1% | 2025-Q4 stale |
| OMERS ADMINISTRATION Corp trimmed | 59,100 | $155K | 0.1% | 2025-Q3 stale |
Ownership over time
Tracked institutional holder count and total shares held by filing quarter (independent scales). The curated-era tail and any mid-ingest latest quarter are handled honestly — a partial quarter is not drawn as a collapse.
Reading this table
Funds hold the same stock for different reasons — an index fund “holds” almost everything, an active manager sizes a name to a mandate and a benchmark, and each fund entered at its own price and time. Because 13F is filed up to 45 days after quarter-end, every row is a backward-looking snapshot; a manager may have traded since. Share-class siblings (a company’s A and C shares) are rolled up to one line so a dual-class name is never double-counted. Compare like-for-like. A large holder is not an endorsement, and a fund exiting is not a warning — this is a starting question, not a verdict.
About 13F filings
A Form 13F is a quarterly disclosure that institutional investment managers with over $100 million in US-listed equities must file with the SEC. In plain English: it is a snapshot of the long stock positions a fund held at the end of a quarter. It covers long US-listed equities only — not short positions, options, cash, or private holdings — and the funds shown are the large sample we track, not the complete 13F universe.