Upstream Bio, Inc. (UPB) Holders & Ownership

Upstream Bio, Inc. (UPB) ownership: Top institutional holder: FMR LLC ($72.91M). Insider activity: Net Seller (0 buys, 20 sells). SEC EDGAR first-party data.

Top Institutional Holders (13F)

Source: SEC Form 13F
HolderSharesMarket ValueReported
FMR LLC8101563.00$72.91M2026-03-31
VANGUARD GROUP INC2388439.00$64.85M2025-12-31
ORBIMED ADVISORS LLC5693589.00$51.24M2026-03-31
JANUS HENDERSON GROUP PLC1527958.00$41.42M2025-12-31
Omega Fund Management, LLC1326293.00$36.01M2025-12-31
VR ADVISER, LLC1169298.00$31.75M2025-12-31
BlackRock, Inc.3370689.00$30.34M2026-03-31
Decheng Capital LLC2724868.00$24.52M2026-03-31

Insider Trading Activity (Form 4)

Source: SEC Form 4
InsiderTransactionValueDate
Sellnull2026-06-16
Sellnull2026-06-16
Sellnull2026-06-16
Sellnull2026-06-16
Sellnull2026-06-16
Sellnull2026-06-09
Sellnull2026-06-09
Sellnull2026-06-09

Back to UPB overview · UPB earnings · All congressional trades

Institutional data from SEC Form 13F. Insider data from SEC Form 4. Congressional data from STOCK Act disclosures. Not personalized investment advice.