Ultragenyx Pharmaceutical Inc. (UP0) Short Interest
XTRA • UP0 • US90400D1081
15.17Last close
Market Closed
As of Nov 3, 2026, ORTEX estimates 4.4% of free float is sold short, cost to borrow 0.42%.
About this data: UP0 short interest, cost to borrow and days to cover
This page tracks how heavily Ultragenyx Pharmaceutical Inc. (XTRA:UP0) is being shorted: ORTEX's daily short interest estimate, the cost to borrow the shares, utilization of the lendable supply and days to cover, next to the official exchange-reported figure.
- Short interest
- The number of shares that have been sold short and not yet bought back, usually shown as a percentage of free float (the shares available to trade). ORTEX estimates it every day from securities-lending data, instead of waiting for exchange reports that are published only twice a month and about two weeks late.
- Cost to borrow
- The annualised fee a short seller pays to borrow the shares, as a percentage of the position's value. A rising cost to borrow means lendable shares are getting scarce and holding the short is getting more expensive.
- Utilization
- The share of the lendable supply of a stock that is currently on loan. Close to 100% means almost no shares are left to borrow.
- Days to cover
- Short interest divided by average daily trading volume: roughly how many days of normal trading it would take for every short seller to buy back their shares.
- Exchange-reported short interest
- The official figure published by the exchange or regulator (in the US, FINRA twice a month). It is accurate but delayed, which is the gap the ORTEX daily and intraday estimates fill.
Source: ORTEX. Some figures are limited on the free view; live data and full history are part of ORTEX Advanced.
UP0 key data
Ultragenyx Pharmaceutical Inc. (XTRA: UP0) has a market capitalization of $1.69B. Last close €15.17 (as of 2026-11-05); 52-week range €13.00 to €15.43. ORTEX data as of 2026-11-03: short interest is 4.43% of free float and the average cost to borrow is 0.42%.