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Alyeska Investment Group, L.P.

Position in UPB — Upstream Bio, Inc.

CIK 1453072 CHICAGO, IL

Position in UPB

as of Mar 31, 2026 · filed May 15, 2026
Position Value
$2,684,961
-$5,414,671 QoQ
Shares Held
298,329
0.0% QoQ
Ownership
0.545%
of shares outstanding
% of Portfolio
0.01%
of 13F equity value
Holder Rank
not a current holder
Holding Since
Dec 2024
5 quarters on record
Voting authority Sole 100% Shared 0% None 0%

Common Shares in UPB Over Time

Shares Held

Position Value (USD)

Position in Biotechnology

Healthcare · as of Jun 30, 2026

Alyeska Investment Group, L.P. holds $989,063,778 across 83 Biotechnology names.

# Ticker Company Shares Value (USD) Open

All Filings in UPB

Export CSV
5 filing rows on record
Report Date Value (USD) Shares
2026-03-31 $2,684,961 298,329
2025-12-31 $8,099,632 298,329
2025-06-30 $933,300 85,000
2025-03-31 $520,200 85,000
2024-12-31 $1,397,400 85,000