CA
UPB

Cliff Asness’s Upstream Bio Inc UPB Stock Holding History

Cliff Asness’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 		$3.77M Buy
544,869
+472,698
+655% +$3.96M ﹤0.01% 2184
2026
Q1 		$650K Buy
72,171
+41,668
+137% +$750K ﹤0.01% 2996
2025
Q4 		$828K Buy
30,503
+549
+2% +$13.7K ﹤0.01% 2654
2025
Q3 		$563K Buy
29,954
+202
+0.7% +$3.14K ﹤0.01% 2759
2025
Q2 		$327K Buy
29,752
+10,930
+58% +$101K ﹤0.01% 2829
2025
Q1 		$115K Buy
+18,822
New +$180K ﹤0.01% 2990

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

Cliff Asness's UPB Position: Q2 2026 in Review

Cliff Asness increased its Upstream Bio Inc (UPB) stake by 655% in Q2 2026, buying an estimated $3.96M and bringing the position to 544,869 shares worth $3.77M. The position accounts for ﹤0.01% of the portfolio, ranked #2184.

Cliff Asness first reported a position in UPB in Q1 2025 and has held it in 6 quarters since. 149 funds tracked by Wall St. Rank hold UPB as of Q2 2026.

  • Cliff Asness held 544,869 shares of Upstream Bio Inc worth $3.77M as of Q2 2026.
  • Cliff Asness bought 472,698 Upstream Bio Inc shares in Q2 2026, an estimated $3.96M.
  • Upstream Bio Inc made up ﹤0.01% of Cliff Asness's portfolio in Q2 2026, its #2184 holding.
  • Cliff Asness first reported a position in Upstream Bio Inc in Q1 2025 and has held it in 6 quarters since.
  • 149 funds tracked by Wall St. Rank held Upstream Bio Inc as of Q2 2026.

Based on AQR Capital Management's 13F filing for Q2 2026, filed 14 Aug 2026.