Gossamer Bio, Inc. (GOSS)

Highly Crowded

Held by 188 of 5,944 reporting institutions (91th percentile) — extremely crowded.

Data as of Q1 2026

Institutional Ownership

73.52%

QoQ Change

-8.78%

Total Value

$54.2B

Shares Outstanding

234.7M

Crowding AnalysisHighly Crowded

Holders188of 5,944

Avg: 68

Uncrowded91th percentileCrowded

Institutional Activity

Buy/Sell Ratio1.04x

80th percentile

117 buying112 selling

+48

New

-57

Closed

-19,342,320

Net shares

Holding Period Distribution

estimate

Median: 2 QAvg: 2.4 QHolders: 188

Ownership Concentration

Top 5: 31.7%Top 10: 49.9%

BlackRock,9.8%

Kalehua Capital Management5.9%

AQR CAPITAL MANAGEMENT5.9%

VANGUARD CAPITAL MANAGEMENT5.4%

ARCH Venture Management,4.7%

Others (183)68.3%

Loading crowding analysis...

Conviction-Weighted Ownership

Median weight: 0.02%Avg weight: 0.33%Max: 2.38%High conviction (>1%): 1

BlackRock,

Kalehua Capital Management

AQR CAPITAL MANAGEMENT

VANGUARD CAPITAL MANAGEMENT

ARCH Venture Management,

Octagon Capital Advisors

Samsara BioCapital,

BALYASNY ASSET MANAGEMENT L.P.

ACADIAN ASSET MANAGEMENT

Siren, L.L.C.

Loading conviction analysis...

Whale Moves Timeline (8 Quarters)

Biggest dollar-value position changes among top 10 holders

NEWKalehua Capital Management$3M10.2M shr

NEWAQR CAPITAL MANAGEMENT$3M10.1M shr

NEWVANGUARD CAPITAL MANAGEMENT$3M9.4M shr

SOLDOctagon Capital Advisors$2M6.2M shr

NEWBALYASNY ASSET MANAGEMENT L.P.$2M5.9M shr

NEWSTATE STREET$29M9.3M shr

NEWHHLR ADVISORS$15M5.0M shr

BOUGHTBlackRock$10M3.2M shr

SOLDOctagon Capital Advisors$10M3.1M shr

BOUGHTSamsara BioCapital$3M1.1M shr

Loading whale moves...

Institutional Trends (8 Quarters)

Loading ownership trends...

Institutional Holders

Loading top holders...