AllianceBernstein
UPB

AllianceBernstein’s Upstream Bio Inc UPB Stock Holding History

AllianceBernstein’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 		$465K Buy
51,680
+20,670
+67% +$173K ﹤0.01% 2763
2026
Q1 		$842K Hold
31,010
– – ﹤0.01% 2410
2025
Q4 		$842K Buy
31,010
+11,160
+56% +$278K ﹤0.01% 2422
2025
Q3 		$373K Sell
19,850
-4,710
-19% -$73.2K ﹤0.01% 2840
2025
Q2 		$270K Sell
24,560
-1,066,626
-98% -$9.85M ﹤0.01% 2966
2025
Q1 		$6.68M Sell
1,091,186
-20,151
-2% -$192K ﹤0.01% 1340
2024
Q4 		$18.3M Buy
+1,111,337
New +$24.8M 0.01% 927

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

AllianceBernstein's UPB Position: Q2 2026 in Review

AllianceBernstein increased its Upstream Bio Inc (UPB) stake by 67% in Q2 2026, buying an estimated $173K and bringing the position to 51,680 shares worth $465K. The position accounts for ﹤0.01% of the portfolio, ranked #2763.

AllianceBernstein first reported a position in UPB in Q4 2024 and has held it in 7 quarters since. The position peaked at $18.3M in Q4 2024. 149 funds tracked by Wall St. Rank hold UPB as of Q2 2026.

  • AllianceBernstein held 51,680 shares of Upstream Bio Inc worth $465K as of Q2 2026.
  • AllianceBernstein bought 20,670 Upstream Bio Inc shares in Q2 2026, an estimated $173K.
  • Upstream Bio Inc made up ﹤0.01% of AllianceBernstein's portfolio in Q2 2026, its #2763 holding.
  • AllianceBernstein first reported a position in Upstream Bio Inc in Q4 2024 and has held it in 7 quarters since.
  • AllianceBernstein's Upstream Bio Inc position peaked at $18.3M in Q4 2024.
  • 149 funds tracked by Wall St. Rank held Upstream Bio Inc as of Q2 2026.

Based on AllianceBernstein's 13F filing for Q2 2026, filed 14 Aug 2026.