John Overdeck’s Upstream Bio Inc UPB Stock Holding History

John Overdeck’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	$293K	Buy	+42,325	New	+$355K	﹤0.01%	4540
2026 Q1	–	Sell	-10,500	Closed	-$285K	–	4999
2025 Q4	$285K	Hold	10,500	–	–	﹤0.01%	3601
2025 Q3	$198K	Buy	+10,500	New	+$163K	﹤0.01%	3380
2025 Q2	–	Sell	-21,789	Closed	-$133K	–	3629
2025 Q1	$133K	Buy	+21,789	New	+$208K	﹤0.01%	2921

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

John Overdeck's UPB Position: Q2 2026 in Review

John Overdeck opened a new position in Upstream Bio Inc (UPB) in Q2 2026: 42,325 shares worth $293K. The stake represents ﹤0.01% of the portfolio and ranks #4540 among its holdings. This is a return to the name: John Overdeck previously reported a position in UPB as recently as Q4 2025.

John Overdeck first reported a position in UPB in Q1 2025 and has held it in 4 quarters since. 149 funds tracked by Wall St. Rank hold UPB as of Q2 2026.

John Overdeck held 42,325 shares of Upstream Bio Inc worth $293K as of Q2 2026.
Upstream Bio Inc was a new John Overdeck position in Q2 2026.
Upstream Bio Inc made up ﹤0.01% of John Overdeck's portfolio in Q2 2026, its #4540 holding.
John Overdeck first reported a position in Upstream Bio Inc in Q1 2025 and has held it in 4 quarters since.
149 funds tracked by Wall St. Rank held Upstream Bio Inc as of Q2 2026.

Based on Two Sigma Investments's 13F filing for Q2 2026, filed 14 Aug 2026.