Shay Capital’s Upstream Bio Inc UPB Stock Holding History

Shay Capital’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	$125K	Buy	18,000 +8,000	+80%	+$67K	0.01%	439
2026 Q1	$90K	Buy	+10,000	New	+$180K	0.01%	440

Other funds holding UPB

Fidelity Investments Boston, Massachusetts $2.3T AUM 54.33% 1-Year Est. Return

OrbiMed New York $5.4B AUM 163.13% 1-Year Est. Return

Norges Bank Oslo, Norway $1T AUM

BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return

Decheng Capital Menlo Park, California $732M AUM 275.56% 1-Year Est. Return

Enavate Sciences Menlo Park, California $345M AUM 134.64% 1-Year Est. Return

Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM

Millennium Management New York $276B AUM 44.8% 1-Year Est. Return

D.E. Shaw & Co New York $210B AUM 57.28% 1-Year Est. Return

JP Morgan Chase New York $1.81T AUM 41.13% 1-Year Est. Return

Shay Capital's UPB Position: Q2 2026 in Review

Shay Capital increased its Upstream Bio Inc (UPB) stake by 80% in Q2 2026, buying an estimated $67K and bringing the position to 18,000 shares worth $125K. The position accounts for 0.01% of the portfolio, ranked #439.

Shay Capital first reported a position in UPB in Q1 2026 and has held it in 2 quarters since. 149 funds tracked by Wall St. Rank hold UPB as of Q2 2026.

Shay Capital held 18,000 shares of Upstream Bio Inc worth $125K as of Q2 2026.
Shay Capital bought 8,000 Upstream Bio Inc shares in Q2 2026, an estimated $67K.
Upstream Bio Inc made up 0.01% of Shay Capital's portfolio in Q2 2026, its #439 holding.
Shay Capital first reported a position in Upstream Bio Inc in Q1 2026 and has held it in 2 quarters since.
149 funds tracked by Wall St. Rank held Upstream Bio Inc as of Q2 2026.

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