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
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 $1.9T AUM 41.92% 1-Year Est. Return
BlackRock
BlackRock New York $5.72T AUM 30.48% 1-Year Est. Return
DC
Decheng Capital Menlo Park, California $661M AUM 299.97% 1-Year Est. Return
ES
Enavate Sciences Menlo Park, California $352M AUM 220.14% 1-Year Est. Return
VCM
Vanguard Capital Management Malvern, Pennsylvania $4.04T AUM
YIH
Y-Intercept (HK) Hong Kong $5.05B AUM 17.89% 1-Year Est. Return
Federated Hermes
Federated Hermes Pittsburgh, Pennsylvania $61.5B AUM 30.7% 1-Year Est. Return
Geode Capital Management
Geode Capital Management Boston, Massachusetts $1.61T AUM 30.72% 1-Year Est. Return
Millennium Management
Millennium Management New York $240B AUM 35.51% 1-Year Est. Return
SAM
SEB Asset Management Stockholm $23.4B AUM

OrbiMed's UPB Position: Q1 2026 in Review

OrbiMed held its Upstream Bio Inc (UPB) position steady in Q1 2026 at 5,693,589 shares worth $51.2M. The position accounts for 1.02% of the portfolio, ranked #32.

OrbiMed first reported a position in UPB in Q4 2024 and has held it in 6 quarters since. The position peaked at $155M in Q4 2025. 140 funds tracked by Wall St. Rank hold UPB as of Q1 2026.

  • OrbiMed held 5,693,589 shares of Upstream Bio Inc worth $51.2M as of Q1 2026.
  • OrbiMed left its Upstream Bio Inc share count unchanged in Q1 2026.
  • Upstream Bio Inc made up 1.02% of OrbiMed's portfolio in Q1 2026, its #32 holding.
  • OrbiMed first reported a position in Upstream Bio Inc in Q4 2024 and has held it in 6 quarters since.
  • OrbiMed's Upstream Bio Inc position peaked at $155M in Q4 2025.
  • 140 funds tracked by Wall St. Rank held Upstream Bio Inc as of Q1 2026.

Based on OrbiMed's 13F filing for Q1 2026, filed 15 May 2026.