BlackRock
UPB

BlackRock’s Upstream Bio Inc UPB Stock Holding History

BlackRock’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 		$26M Buy
3,753,358
+382,669
+11% +$3.21M ﹤0.01% 3099
2026
Q1 		$30.3M Buy
3,370,689
+26,185
+0.8% +$471K ﹤0.01% 2816
2025
Q4 		$90.8M Buy
3,344,504
+740,798
+28% +$18.4M ﹤0.01% 2162
2025
Q3 		$49M Buy
2,603,706
+507,200
+24% +$7.88M ﹤0.01% 2512
2025
Q2 		$23M Buy
2,096,506
+910,738
+77% +$8.41M ﹤0.01% 2936
2025
Q1 		$7.26M Buy
1,185,768
+67,968
+6% +$649K ﹤0.01% 3478
2024
Q4 		$18.4M Buy
+1,117,800
New +$25M ﹤0.01% 3102

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
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

BlackRock's UPB Position: Q2 2026 in Review

BlackRock increased its Upstream Bio Inc (UPB) stake by 11% in Q2 2026, buying an estimated $3.21M and bringing the position to 3,753,358 shares worth $26M. The position accounts for ﹤0.01% of the portfolio, ranked #3099.

BlackRock first reported a position in UPB in Q4 2024 and has held it in 7 quarters since. The position peaked at $90.8M in Q4 2025. 149 funds tracked by Wall St. Rank hold UPB as of Q2 2026.

  • BlackRock held 3,753,358 shares of Upstream Bio Inc worth $26M as of Q2 2026.
  • BlackRock bought 382,669 Upstream Bio Inc shares in Q2 2026, an estimated $3.21M.
  • Upstream Bio Inc made up ﹤0.01% of BlackRock's portfolio in Q2 2026, its #3099 holding.
  • BlackRock first reported a position in Upstream Bio Inc in Q4 2024 and has held it in 7 quarters since.
  • BlackRock's Upstream Bio Inc position peaked at $90.8M in Q4 2025.
  • 149 funds tracked by Wall St. Rank held Upstream Bio Inc as of Q2 2026.

Based on BlackRock's 13F filing for Q2 2026, filed 7 Aug 2026.