Renaissance Technologies (RenTech)'s UPB Position Overview
Renaissance Technologies (RenTech) (via Renaissance Technologies LLC) currently holds 131,300 shares of Upstream Bio, Inc. (UPB) worth $908,596, representing 0.00% of the portfolio. First purchased in 2025-Q4, this short-term holding has been held for 3 quarters.
Based on 13F filings, Renaissance Technologies (RenTech) has maintained this position in UPB for several quarters, showing initial confidence in the investment. Largest addition occurred in Q2 2026, adding 69,200 shares.
Analysis based on 13F filings available since 2013 Q2
Renaissance Technologies (RenTech)'s Upstream Bio (UPB) Holding Value Over Time
Track share changes against reported price movement
Quarterly Upstream Bio (UPB) Trades by Renaissance Technologies (RenTech)
| Report Date | Bought/Sold (Sh.) | % Change | Qtr. End Shares | Reported Price |
|---|---|---|---|---|
| Q2 2026 | +69,200 | Add 111.43% | 131,300 | $6.92 |
| Q1 2026 | +45,700 | Add 278.66% | 62,100 | $9.00 |
| Q4 2025 | +16,400 | New Buy | 16,400 | $27.15 |
Renaissance Technologies (RenTech)'s Upstream Bio Investment FAQs
Renaissance Technologies (RenTech) first purchased Upstream Bio, Inc. (UPB) in Q4 2025, acquiring 16,400 shares, as reported in their 13F filing for that period. Note: Analysis reflects filings available since Q2 2013; earlier records may be incomplete.
Renaissance Technologies (RenTech) has held Upstream Bio, Inc. (UPB) for 3 quarters since Q4 2025.
Renaissance Technologies (RenTech)'s largest addition to Upstream Bio, Inc. (UPB) was in Q2 2026, adding 131,300 shares worth $908,596.
According to the latest 13F filing for Q2 2026, Renaissance Technologies (RenTech)'s firm, Renaissance Technologies LLC, owns 131,300 shares of Upstream Bio, Inc. (UPB), valued at approximately $908,596.
As of the Q2 2026 filing, Upstream Bio, Inc. (UPB) represents approximately 0.00% of Renaissance Technologies (RenTech)'s publicly disclosed stock portfolio, making it one of their key holdings.
Renaissance Technologies (RenTech)'s peak holding in Upstream Bio, Inc. (UPB) was 131,300 shares, as reported at the end of Q2 2026.