Wellington Management Group
UPB

Wellington Management Group’s Upstream Bio Inc UPB Stock Holding History

Wellington Management Group’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 		$3.08M Sell
342,353
-552,380
-62% -$9.94M ﹤0.01% 1482
2025
Q4 		$24.3M Sell
894,733
-230,662
-20% -$5.74M ﹤0.01% 967
2025
Q3 		$21.2M Sell
1,125,395
-99,900
-8% -$1.55M ﹤0.01% 992
2025
Q2 		$13.5M Sell
1,225,295
-88,162
-7% -$814K ﹤0.01% 1112
2025
Q1 		$8.03M Sell
1,313,457
-269,697
-17% -$2.58M ﹤0.01% 1258
2024
Q4 		$25.6M Buy
+1,583,154
New +$35.3M ﹤0.01% 895

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

Wellington Management Group's UPB Position: Q1 2026 in Review

Wellington Management Group reduced its Upstream Bio Inc (UPB) stake by 62% in Q1 2026, selling an estimated $9.94M and leaving 342,353 shares worth $3.08M. The position accounts for ﹤0.01% of the portfolio, ranked #1482.

Wellington Management Group first reported a position in UPB in Q4 2024 and has held it in 6 quarters since. The position peaked at $25.6M in Q4 2024. 140 funds tracked by Wall St. Rank hold UPB as of Q1 2026.

  • Wellington Management Group held 342,353 shares of Upstream Bio Inc worth $3.08M as of Q1 2026.
  • Wellington Management Group sold 552,380 Upstream Bio Inc shares in Q1 2026, an estimated $9.94M.
  • Upstream Bio Inc made up ﹤0.01% of Wellington Management Group's portfolio in Q1 2026, its #1482 holding.
  • Wellington Management Group first reported a position in Upstream Bio Inc in Q4 2024 and has held it in 6 quarters since.
  • Wellington Management Group's Upstream Bio Inc position peaked at $25.6M in Q4 2024.
  • 140 funds tracked by Wall St. Rank held Upstream Bio Inc as of Q1 2026.

Based on Wellington Management Group's 13F filing for Q1 2026, filed 15 May 2026.