Market Guide 03
FINRA says short interest is a snapshot of total open short positions on a given settlement date, reported twice a month by firms on a per-security basis. That makes it useful, but it also means it is not the same thing as daily short sale volume.
Why this note matters
Short interest often gets discussed like a live sentiment meter. The official FINRA guidance is stricter: it is a dated position snapshot with a specific reporting cycle and clear boundaries.
FINRA says short interest is a snapshot of the total open short positions existing on the books and records of brokerage firms for all equity securities on a given settlement date. It also says firms report that information twice a month.
That wording matters because it prevents a common mistake. Short interest is not a continuous real-time readout. It is a dated position snapshot published on a fixed reporting cadence.
FINRA explicitly says short interest position data does not equate to the daily short sale volume data posted on its website. The reason is straightforward: short interest measures open positions at a point in time, while the daily short sale volume file reflects aggregated short-sale trading activity on a trade date.
A stock can show heavy daily short-sale activity without that activity turning into a matching open short position at the settlement-date snapshot, and an open short position can persist long after the trade date when it was created.
FINRA's reporting page says firms must report short interest positions by 6 p.m. Eastern Time on the second business day after the designated reporting settlement date. That timetable gives the data an official cadence and an obvious freshness limit.
For Hynexly readers, the practical rule is simple: short interest is useful when you respect the reporting window and the distinction between positions and trade flow. It becomes misleading when readers treat it like a live tape or confuse it with daily short-sale prints.
FINRA explains what short interest measures, how often it is reported, and why it should not be confused with short sale volume data.
Open sourceFINRA explains the reporting schedule, the filing deadline, and the Rule 4560 framework for short interest submissions.
Open source