O
UPB

OrbiMed’s Upstream Bio Inc UPB Stock Holding History

OrbiMed’s Portfolio UPB Stock Details UPB Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2026
Q2 		$39.4M Hold
5,693,589
– – 0.73% 42
2026
Q1 		$51.2M Hold
5,693,589
– – 1.02% 32
2025
Q4 		$155M Hold
5,693,589
– – 3.16% 6
2025
Q3 		$107M Hold
5,693,589
– – 2.52% 12
2025
Q2 		$62.5M Hold
5,693,589
– – 1.56% 20
2025
Q1 		$34.8M Hold
5,693,589
– – 0.83% 32
2024
Q4 		$93.6M Buy
+5,693,589
New +$127M 1.93% 15

Other funds holding UPB

Fidelity Investments
Fidelity Investments Boston, Massachusetts $2.3T AUM 54.33% 1-Year Est. Return
Norges Bank
Norges Bank Oslo, Norway $1T AUM
BlackRock
BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return
DC
Decheng Capital Menlo Park, California $732M AUM 275.56% 1-Year Est. Return
ES
Enavate Sciences Menlo Park, California $345M AUM 134.64% 1-Year Est. Return
Vanguard Capital Management
Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM
Millennium Management
Millennium Management New York $276B AUM 44.8% 1-Year Est. Return
D.E. Shaw & Co
D.E. Shaw & Co New York $210B AUM 57.28% 1-Year Est. Return
JP Morgan Chase
JP Morgan Chase New York $1.81T AUM 41.13% 1-Year Est. Return
Qube Research & Technologies (QRT)
Qube Research & Technologies (QRT) London, United Kingdom $108B AUM 37.29% 1-Year Est. Return

OrbiMed's UPB Position: Q2 2026 in Review

OrbiMed held its Upstream Bio Inc (UPB) position steady in Q2 2026 at 5,693,589 shares worth $39.4M. The position accounts for 0.73% of the portfolio, ranked #42.

OrbiMed first reported a position in UPB in Q4 2024 and has held it in 7 quarters since. The position peaked at $155M in Q4 2025. 149 funds tracked by Wall St. Rank hold UPB as of Q2 2026.

  • OrbiMed held 5,693,589 shares of Upstream Bio Inc worth $39.4M as of Q2 2026.
  • OrbiMed left its Upstream Bio Inc share count unchanged in Q2 2026.
  • Upstream Bio Inc made up 0.73% of OrbiMed's portfolio in Q2 2026, its #42 holding.
  • OrbiMed first reported a position in Upstream Bio Inc in Q4 2024 and has held it in 7 quarters since.
  • OrbiMed's Upstream Bio Inc position peaked at $155M in Q4 2025.
  • 149 funds tracked by Wall St. Rank held Upstream Bio Inc as of Q2 2026.

Based on OrbiMed's 13F filing for Q2 2026, filed 14 Aug 2026.