SB
UPB

Samsara BioCapital’s Upstream Bio Inc UPB Stock Holding History

Samsara BioCapital’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 		$6.62M Hold
736,047
– – 0.64% 16
2025
Q4 		$20M Sell
736,047
-226,107
-24% -$5.63M 2.06% 9
2025
Q3 		$18.1M Sell
962,154
-481,077
-33% -$7.47M 2.36% 7
2025
Q2 		$15.8M Sell
1,443,231
-623,915
-30% -$5.76M 3.24% 7
2025
Q1 		$12.7M Sell
2,067,146
-150,000
-7% -$1.43M 2.26% 10
2024
Q4 		$36.4M Buy
+2,217,146
New +$49.5M 5% 6

Other funds holding UPB

Fidelity Investments
Fidelity Investments Boston, Massachusetts $1.9T AUM 41.92% 1-Year Est. Return
O
OrbiMed New York $5.05B AUM 125.28% 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

Samsara BioCapital's UPB Position: Q1 2026 in Review

Samsara BioCapital held its Upstream Bio Inc (UPB) position steady in Q1 2026 at 736,047 shares worth $6.62M. The position accounts for 0.64% of the portfolio, ranked #16.

Samsara BioCapital first reported a position in UPB in Q4 2024 and has held it in 6 quarters since. The position peaked at $36.4M in Q4 2024. 140 funds tracked by Wall St. Rank hold UPB as of Q1 2026.

  • Samsara BioCapital held 736,047 shares of Upstream Bio Inc worth $6.62M as of Q1 2026.
  • Samsara BioCapital left its Upstream Bio Inc share count unchanged in Q1 2026.
  • Upstream Bio Inc made up 0.64% of Samsara BioCapital's portfolio in Q1 2026, its #16 holding.
  • Samsara BioCapital first reported a position in Upstream Bio Inc in Q4 2024 and has held it in 6 quarters since.
  • Samsara BioCapital's Upstream Bio Inc position peaked at $36.4M in Q4 2024.
  • 140 funds tracked by Wall St. Rank held Upstream Bio Inc as of Q1 2026.

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