Short volume
🟢 plain english
How many of today's SELL orders were marked as short sales. It publishes daily, which makes it tempting to read as a live squeeze gauge — but it structurally cannot show you the thing squeeze-watchers want most: shorts buying back.
🔬 technical
Only sell-side short executions are marked. A short seller closing their position buys, and a buy-to-cover is indistinguishable from any other buy in this data. So a collapsing short-volume ratio on a big up day tells you the marginal SELLER stopped dominating — it can never tell you covering happened. The first data that can actually settle covering is the next Short interest (SI) settlement print, weeks later. Treating short volume as a covering signal is one of the most common squeeze-analysis errors.