Renaissance Technologies (RenTech)'s RARE Position Overview
Renaissance Technologies (RenTech) (via Renaissance Technologies LLC (Rentech)) currently holds 366,100 shares of Ultragenyx Pharmaceutical Inc. (RARE) worth $8.42 M, representing 0.01% of the portfolio. First purchased in 2015-Q3, this medium-term investment has been held for 18 quarters.
Based on 13F filings, Renaissance Technologies (RenTech) has maintained a strategic position in RARE, demonstrating sustained confidence in this investment. Largest addition occurred in Q4 2025, adding 344,200 shares. Largest reduction occurred in Q3 2021, reducing 390,800 shares.
Analysis based on 13F filings available since 2013 Q2
Renaissance Technologies (RenTech)'s Ultragenyx Pharmaceutical (RARE) Holding Value Over Time
Track share changes against reported price movement
Quarterly Ultragenyx Pharmaceutical (RARE) Trades by Renaissance Technologies (RenTech)
| Report Date | Bought/Sold (Sh.) | % Change | Qtr. End Shares | Reported Price |
|---|---|---|---|---|
| Q4 2025 | +344,200 | Add 1571.69% | 366,100 | $23.00 |
| Q3 2025 | -186,400 | Reduce 89.49% | 21,900 | $30.08 |
| Q2 2025 | -91,300 | Reduce 30.47% | 208,300 | $36.36 |
| Q1 2025 | +44,900 | Add 17.63% | 299,600 | $36.21 |
| Q4 2024 | +72,600 | Add 39.87% | 254,700 | $42.07 |
| Q3 2024 | +182,100 | New Buy | 182,100 | $55.55 |
| Q3 2023 | -19,600 | Sold Out | 0 | $0.00 |
| Q2 2023 | +19,600 | New Buy | 19,600 | $0.05 |
| Q1 2022 | -47,400 | Sold Out | 0 | $0.00 |
| Q4 2021 | -24,200 | Reduce 33.80% | 47,400 | $84.09 |
| Q3 2021 | -390,800 | Reduce 84.52% | 71,600 | $90.20 |
| Q2 2021 | +317,600 | Add 219.34% | 462,400 | $95.35 |
| Q1 2021 | +50,000 | Add 52.74% | 144,800 | $113.86 |
| Q4 2020 | +94,800 | New Buy | 94,800 | $138.43 |
| Q2 2016 | -54,400 | Sold Out | 0 | $0.00 |
| Q1 2016 | +54,400 | New Buy | 54,400 | $63.31 |
| Q4 2015 | -3,200 | Sold Out | 0 | $0.00 |
| Q3 2015 | +3,200 | New Buy | 3,200 | $96.25 |
Renaissance Technologies (RenTech)'s Ultragenyx Pharmaceutical Investment FAQs
Renaissance Technologies (RenTech) first purchased Ultragenyx Pharmaceutical Inc. (RARE) in Q3 2015, acquiring 3,200 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 Ultragenyx Pharmaceutical Inc. (RARE) for 18 quarters since Q3 2015.
Renaissance Technologies (RenTech)'s largest addition to Ultragenyx Pharmaceutical Inc. (RARE) was in Q4 2025, adding 366,100 shares worth $8.42 M.
According to the latest 13F filing for Q4 2025, Renaissance Technologies (RenTech)'s firm, Renaissance Technologies LLC (Rentech), owns 366,100 shares of Ultragenyx Pharmaceutical Inc. (RARE), valued at approximately $8.42 M.
As of the Q4 2025 filing, Ultragenyx Pharmaceutical Inc. (RARE) represents approximately 0.01% of Renaissance Technologies (RenTech)'s publicly disclosed stock portfolio, making it one of their key holdings.
Renaissance Technologies (RenTech)'s peak holding in Ultragenyx Pharmaceutical Inc. (RARE) was 462,400 shares, as reported at the end of Q2 2021.