Renaissance Technologies’s Upstream Bio Inc UPB Stock Holding History

Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake
Trade Value Portfolio Weight Portfolio Position
2026
Q1
$559K Buy
62,100
+45,700
+279% +$822K ﹤0.01% 2558
2025
Q4
$445K Buy
+16,400
New +$408K ﹤0.01% 2620

Other funds holding UPB

Renaissance Technologies's UPB Position: Q1 2026 in Review

Renaissance Technologies increased its Upstream Bio Inc (UPB) stake by 279% in Q1 2026, buying an estimated $822K and bringing the position to 62,100 shares worth $559K. The position accounts for ﹤0.01% of the portfolio, ranked #2558.

Renaissance Technologies first reported a position in UPB in Q4 2025 and has held it in 2 quarters since. 140 funds tracked by Wall St. Rank hold UPB as of Q1 2026.

  • Renaissance Technologies held 62,100 shares of Upstream Bio Inc worth $559K as of Q1 2026.
  • Renaissance Technologies bought 45,700 Upstream Bio Inc shares in Q1 2026, an estimated $822K.
  • Upstream Bio Inc made up ﹤0.01% of Renaissance Technologies's portfolio in Q1 2026, its #2558 holding.
  • Renaissance Technologies first reported a position in Upstream Bio Inc in Q4 2025 and has held it in 2 quarters since.
  • 140 funds tracked by Wall St. Rank held Upstream Bio Inc as of Q1 2026.

Based on Renaissance Technologies's 13F filing for Q1 2026, filed 14 May 2026.