BCLSI
UPB

Bain Capital Life Sciences Investors’s Upstream Bio Inc UPB Stock Holding History

Bain Capital Life Sciences Investors’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 		$7.8M Sell
867,211
-462,333
-35% -$8.32M 0.7% 18
2025
Q4 		$36.1M Sell
1,329,544
-1,109,994
-46% -$27.6M 2.76% 7
2025
Q3 		$45.9M Hold
2,439,538
– – 3.05% 9
2025
Q2 		$26.8M Buy
2,439,538
+144,216
+6% +$1.33M 3.35% 11
2025
Q1 		$14M Hold
2,295,322
– – 2.08% 11
2024
Q4 		$37.7M Buy
+2,295,322
New +$51.3M 4.44% 8

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

Bain Capital Life Sciences Investors's UPB Position: Q1 2026 in Review

Bain Capital Life Sciences Investors reduced its Upstream Bio Inc (UPB) stake by 35% in Q1 2026, selling an estimated $8.32M and leaving 867,211 shares worth $7.8M. The position accounts for 0.7% of the portfolio, ranked #18.

Bain Capital Life Sciences Investors first reported a position in UPB in Q4 2024 and has held it in 6 quarters since. The position peaked at $45.9M in Q3 2025. 140 funds tracked by Wall St. Rank hold UPB as of Q1 2026.

  • Bain Capital Life Sciences Investors held 867,211 shares of Upstream Bio Inc worth $7.8M as of Q1 2026.
  • Bain Capital Life Sciences Investors sold 462,333 Upstream Bio Inc shares in Q1 2026, an estimated $8.32M.
  • Upstream Bio Inc made up 0.7% of Bain Capital Life Sciences Investors's portfolio in Q1 2026, its #18 holding.
  • Bain Capital Life Sciences Investors first reported a position in Upstream Bio Inc in Q4 2024 and has held it in 6 quarters since.
  • Bain Capital Life Sciences Investors's Upstream Bio Inc position peaked at $45.9M in Q3 2025.
  • 140 funds tracked by Wall St. Rank held Upstream Bio Inc as of Q1 2026.

Based on Bain Capital Life Sciences Investors's 13F filing for Q1 2026, filed 15 May 2026.