Glossary
The terms behind the numbers on this site, in plain English; each one opens to a fuller explanation. For how the data is collected and validated, see the methodology; for longer explanations, the guides.
- Short selling
- Selling a borrowed share in the expectation of buying it back later at a lower price, returning it to the lender and keeping the difference. Read more
- Net short position
- A holder's short exposure to a company minus their long exposure, expressed as a percentage of the company's issued share capital. Read more
- Short interest
- The general term for how much of a company's share capital is held short; each regime measures it differently. Read more
- FINRA short interest (US)
- The US measure: broker-dealers report the short positions on their books as of two settlement dates a month, and FINRA publishes one consolidated total per security about nine business days later. Read more
- Aggregate net short position (ANSP)
- The UK measure, published daily by the FCA from 13 July 2026: the sum of every individual net short position of at least 0.2% of a company's issued share capital. Read more
- Named register
- The EU-style publication model: each individual net short position of 0.5% or more of share capital is published with the position holder's name. Read more
- Disclosure threshold
- The size a position must reach before it becomes publicly visible: 0.2% of capital in the UK aggregate, 0.5% named in EU markets, close to everything in Australia. Read more
- Disclosure floor
- Why published figures understate true short interest where thresholds apply: positions below the threshold exist but are invisible. Read more
- Position date vs publication date
- The position date is the day a short position existed; the publication date is the day the regulator released the figure. They are never the same day. Read more
- Settlement date
- The date on which a share trade is completed by delivery and payment; FINRA's short interest is counted as of settlement, not trade date. Read more
- T+4 (Australia)
- ASIC publishes each trading day's aggregate short positions four trading days in arrears. Read more
- Reportable Shares List (RSL)
- The FCA's list of the shares within scope of the UK short-selling regime; a company must be on it for positions in it to be reportable. Read more
- Revision
- A regulator amending a previously published figure; both the old and new values are archived here and revised figures carry a marker. Read more
- Percentage points (pp)
- How changes are measured on this site: a move from 2.0% to 3.0% of share capital is a rise of 1.0 percentage point, not a 50% rise. Read more
- Covering
- Buying back borrowed shares to close a short position; sustained covering shows up as a falling disclosed short position. Read more
- Short squeeze
- A rapid price rise that pressures short sellers to buy back shares, which can push the price higher still. Read more
- Days to cover (short interest ratio)
- Short interest divided by average daily trading volume: how many days of typical trading it would take shorts to exit. Shown for US stocks only, as FINRA's own figure. Read more
- Gross vs net short position
- Gross is every short exposure added up; net subtracts long exposure in the same company. Disclosure regimes report net. Read more
- Position holder
- The entity named on an EU register as holding a disclosed net short position: usually an asset manager or hedge fund, not the individual trader. Read more
- Naked short selling
- Selling shares short without first borrowing them or arranging to borrow them; restricted in the US by Regulation SHO's locate requirement and banned outright in the EU and UK. Read more
- Locate requirement
- The US rule that a broker must identify a source of borrowable shares before accepting a short sale order. Read more
- Regulation SHO
- The SEC's rulebook for short sales in the US: the locate requirement, close-out obligations for fails to deliver, and the threshold securities lists. Read more
- Fails to deliver (FTD)
- Shares that were sold but not delivered at settlement; the SEC publishes aggregate fails twice a month. Read more
- Uptick rule (short sale circuit breaker)
- The US rule that restricts short selling in a stock for the rest of the day and the next day once it has fallen 10% from the previous close. Read more
- Market maker exemption
- Positions taken by market makers in the course of providing liquidity are exempt from EU and UK short position disclosure, so they never appear on registers. Read more
- Short Selling Regulation (SSR)
- The EU regulation (236/2012) that created the 0.1% notification and 0.5% public disclosure thresholds for net short positions in shares, retained in UK law after Brexit and reformed there in 2026. Read more
- Delisting and short positions
- When a company leaves the market its short data stops; positions are unwound in a takeover, or left to the bankruptcy process, and the history is kept here on an archive page. Read more