Upstream Bio, Inc. (UPB) Short Interest, Short Squeeze & Borrow Rates ● LIVE

Introduction

This page gathers everything we track on the short side of Upstream Bio, Inc. (UPB) in one place, ordered by how quickly each number changes. The fastest moving figures, like the borrow fee, sit near the top. Daily figures such as short volume and fails to deliver come next. The slowest data, the official short interest that exchanges publish twice a month, sits at the bottom. Reading it top to bottom gives you a feel for what is happening right now versus what has built up over time.

Reported short interest for UPB at each date, shown with days to cover and short interest as a percent of float. Short interest updates twice a month; the percentages are recomputed as float changes.

The raw short interest NASDAQ publishes at each settlement date, with the publication date and the change from the prior period. These are the exchange own figures and are not adjusted for stock splits.

How many UPB shares were sold short off exchange each day, summed across the reporting venues we track. It includes market maker hedging and other routine activity, so a high reading is normal and is not the same as outstanding short interest.

Off-exchange volume combined with the on-exchange venues we track. The aggregate columns cover those venues only, not every place UPB trades, so treat the totals as a representative sample rather than a full market count.

UPB shares that did not settle on time, reported by the SEC. Each figure is a running balance on a given date rather than a daily tally, and it is not added up across dates. Fails happen for many ordinary reasons and are not on their own a sign of anything improper.

How many UPB shares one large prime broker had available to lend at each timestamp. It is a sample of a single lender, not the total shortable pool and not the short interest, but the direction over a day or two is a useful read on demand. Last update 7 minutes ago.

The annualized rate a short seller pays to borrow UPB. The latest reading is 65.45%. A high or rising fee means shares are getting harder and more expensive to short, which is one of the conditions that can feed a squeeze.