Marshall Wace
UPB

Marshall Wace’s Upstream Bio Inc UPB Stock Holding History

Marshall Wace’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 		$601K Sell
66,770
-277,021
-81% -$4.98M ﹤0.01% 2363
2025
Q4 		$9.33M Sell
343,791
-524,208
-60% -$13M 0.01% 899
2025
Q3 		$16.3M Buy
867,999
+577,473
+199% +$8.97M 0.02% 742
2025
Q2 		$3.19M Sell
290,526
-14,437
-5% -$133K ﹤0.01% 1346
2025
Q1 		$1.87M Buy
304,963
+14,229
+5% +$136K ﹤0.01% 1495
2024
Q4 		$4.78M Buy
+290,734
New +$6.49M 0.01% 1085

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

Marshall Wace's UPB Position: Q1 2026 in Review

Marshall Wace reduced its Upstream Bio Inc (UPB) stake by 81% in Q1 2026, selling an estimated $4.98M and leaving 66,770 shares worth $601K. The position accounts for ﹤0.01% of the portfolio, ranked #2363.

Marshall Wace first reported a position in UPB in Q4 2024 and has held it in 6 quarters since. The position peaked at $16.3M in Q3 2025. 140 funds tracked by Wall St. Rank hold UPB as of Q1 2026.

  • Marshall Wace held 66,770 shares of Upstream Bio Inc worth $601K as of Q1 2026.
  • Marshall Wace sold 277,021 Upstream Bio Inc shares in Q1 2026, an estimated $4.98M.
  • Upstream Bio Inc made up ﹤0.01% of Marshall Wace's portfolio in Q1 2026, its #2363 holding.
  • Marshall Wace first reported a position in Upstream Bio Inc in Q4 2024 and has held it in 6 quarters since.
  • Marshall Wace's Upstream Bio Inc position peaked at $16.3M in Q3 2025.
  • 140 funds tracked by Wall St. Rank held Upstream Bio Inc as of Q1 2026.

Based on Marshall Wace's 13F filing for Q1 2026, filed 15 May 2026.