Simplex Trading
UPB

Simplex Trading’s Upstream Bio Inc UPB Stock Holding History

Simplex Trading’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 		$9.69K Sell
1,400
-14,400
-91% -$121K ﹤0.01% 7719
2026
Q1 		$142K Buy
15,800
+11,300
+251% +$203K ﹤0.01% 4689
2025
Q4 		$122K Sell
4,500
-4,000
-47% -$99.6K ﹤0.01% 4777
2025
Q3 		$159K Buy
+8,500
New +$132K ﹤0.01% 5215

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

Simplex Trading's UPB Position: Q2 2026 in Review

Simplex Trading opened a new position in Upstream Bio Inc (UPB) in Q2 2026: 20 shares worth $138. The stake represents ﹤0.01% of the portfolio and ranks #9080 among its holdings. This is a return to the name: Simplex Trading previously reported a position in UPB as recently as Q4 2025.

Simplex Trading first reported a position in UPB in Q4 2025 and has held it in 2 quarters since. The position peaked at $12.7K in Q4 2025. 149 funds tracked by Wall St. Rank hold UPB as of Q2 2026.

  • Simplex Trading held 20 shares of Upstream Bio Inc worth $138 as of Q2 2026.
  • Upstream Bio Inc was a new Simplex Trading position in Q2 2026.
  • Upstream Bio Inc made up ﹤0.01% of Simplex Trading's portfolio in Q2 2026, its #9080 holding.
  • Simplex Trading first reported a position in Upstream Bio Inc in Q4 2025 and has held it in 2 quarters since.
  • Simplex Trading's Upstream Bio Inc position peaked at $12.7K in Q4 2025.
  • 149 funds tracked by Wall St. Rank held Upstream Bio Inc as of Q2 2026.

Based on Simplex Trading's 13F filing for Q2 2026, filed 12 Aug 2026.