FINRA Short Interest / Short Ratio
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Definition
Exchange-reported short interest (shares sold short) published twice monthly by FINRA, plus derived measures like the short ratio (days-to-cover) and short percent of float, gauging bearish positioning and squeeze potential.
How to read it
Short interest counts shares sold short but not yet covered. FINRA collects it as of the settlement dates around mid-month and month-end and publishes it roughly 8-9 business days later, so it carries a meaningful reporting lag. The short ratio (short interest divided by average daily volume, i.e. days-to-cover) estimates how long shorts would take to buy back. High short interest can mean bearish conviction, but also fuel for a short squeeze if price rises and shorts scramble to cover. Percent of float contextualizes the raw number against tradable shares.
How practitioners use it
Used as context among multiple indicators — never as a standalone signal to act.
Less common professional uses
The bi-monthly settlement-plus-8-day publication lag is the central pitfall: the data can be two-plus weeks stale by release, so a 'high short interest' headline may already have been covered. Short interest excludes short exposure expressed via options, swaps, and ETFs, so a low equity short interest can understate true bearish positioning. Squeeze setups need a catalyst plus high days-to-cover plus a rising price; high short interest alone is not a signal, since heavily shorted names can stay depressed for good fundamental reasons. Reg SHO and threshold-list securities carry settlement dynamics (fails-to-deliver, buy-ins) that can amplify squeezes beyond what raw short interest implies. Corporate actions, index rebalances, and merger arbitrage can inflate short interest for mechanical reasons unrelated to directional sentiment.
Sources & provenance
FINRA bi-monthly short interest (settlement mid/end month, ~8-9 business-day publication lag); Exchange average daily volume (for days-to-cover)
This page is educational content published by Pachira Aquatica Global LLC. It is not investment advice and not a recommendation.