BCM
UPB

Boxer Capital Management’s Upstream Bio Inc UPB Stock Holding History

Boxer Capital Management’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 		$1.04M Hold
150,000
– – 0.08% 59
2026
Q1 		$1.35M Hold
150,000
– – 0.18% 49
2025
Q4 		$4.07M Buy
+150,000
New +$3.73M 0.89% 30

Other funds holding UPB

Fidelity Investments
Fidelity Investments Boston, Massachusetts $2.3T AUM 54.33% 1-Year Est. Return
O
OrbiMed New York $5.4B AUM 163.13% 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

Boxer Capital Management's UPB Position: Q2 2026 in Review

Boxer Capital Management held its Upstream Bio Inc (UPB) position steady in Q2 2026 at 150,000 shares worth $1.04M. The position accounts for 0.08% of the portfolio, ranked #59.

Boxer Capital Management first reported a position in UPB in Q4 2025 and has held it in 3 quarters since. The position peaked at $4.07M in Q4 2025. 148 funds tracked by Wall St. Rank hold UPB as of Q2 2026.

  • Boxer Capital Management held 150,000 shares of Upstream Bio Inc worth $1.04M as of Q2 2026.
  • Boxer Capital Management left its Upstream Bio Inc share count unchanged in Q2 2026.
  • Upstream Bio Inc made up 0.08% of Boxer Capital Management's portfolio in Q2 2026, its #59 holding.
  • Boxer Capital Management first reported a position in Upstream Bio Inc in Q4 2025 and has held it in 3 quarters since.
  • Boxer Capital Management's Upstream Bio Inc position peaked at $4.07M in Q4 2025.
  • 148 funds tracked by Wall St. Rank held Upstream Bio Inc as of Q2 2026.

Based on Boxer Capital Management's 13F filing for Q2 2026, filed 14 Aug 2026.