Short selling 101

Short interest numbers look scary in headlines. Here is what they measure — and what they cannot tell you.

The basic idea

Short selling borrows shares, sells them now, and hopes to buy them back cheaper later. If the price rises instead, losses can grow without a fixed ceiling. This site reports published positioning stats; it does not recommend shorting or covering.

Glossary

Float: Shares available for public trading (roughly). Short % of Float asks: of those shares, what share is currently reported short?
Short interest: A snapshot of open short positions from exchange/FINRA reporting cycles — not a live tape of every short sale today.
Days to cover: Roughly short interest divided by average daily volume. Higher values mean it could take longer to unwind shorts if everyone rushed at once — a liquidity story, not a countdown timer.
Short squeeze: A feedback loop where rising prices force short covering, which can push prices further. Elevated short interest raises the potential for squeezes; it does not cause one by itself.

Short interest vs short volume

Short interest is the inventory of open shorts on a settlement date (biweekly from FINRA for many names). Short volume is how much selling on a given day was marked short. Mixing them up is a common headline error — This site labels the FINRA as-of date on every short interest figure.