Market-data field guide
Separate the position from the activity.
Short interest measures an outstanding position at a reporting snapshot. Short-sale volume measures trading activity during a period. A timeline makes the difference clear—and shows why one cannot be used as a shortcut for the other.
By GapperzUpdated
Opened and closed in one day.
Daily transactions and a settlement-date snapshot measure different things.
- 10:00 · Sell short 1,000
The short sale contributes to applicable daily volume.
- 11:00 · Buy to close 1,000
The example position is fully closed.
- Snapshot · No open position
There is no remaining position from this example to report.
- 01A position snapshot and a transaction total measure different things.
- 02A short sale closed during the day can add volume without leaving an open position.
- 03Read reporting dates and venue coverage beside every short-data field.
Position and activity belong on different timelines.
Short interest counts open short positions as of the relevant reporting settlement date. FINRA's reporting cycle is twice monthly. The published information therefore describes a dated snapshot rather than a continuous live position counter.
Short-sale volume counts qualifying transactions marked as short during a specified period and within the dataset's coverage. A daily volume total describes activity. It does not tell you how much of that activity remains an open short position at the reporting snapshot.
The distinction matters whenever a chart, feed, or commentary presents a large short-volume percentage. Start with the definition and coverage of that percentage before using it in a research note. The denominator belongs to the same transaction dataset.
| Measure | What it records | Date and coverage |
|---|---|---|
| Short interest | Outstanding short positions | Reporting settlement-date snapshot; published later |
| Short-sale volume | Qualifying short-sale transactions | Activity during the file's period and covered venues |
| Short-volume percentage | Short volume divided by matching covered total volume | Transaction mix within that dataset |
One thousand shares can appear in one measure only.
In a fictional example, a participant sells 1,000 shares short at 10:00 a.m. and buys 1,000 shares to close that position at 11:00 a.m. The opening sale contributes to the relevant short-sale activity record. By the later position snapshot, this example leaves no open short position.
Change the example so the participant holds the position across the reporting settlement date. The outstanding position now belongs in the relevant position snapshot. The original transaction volume and the later position measure remain different records.
This is why summing daily short-sale volume cannot reconstruct short interest. Activity can open and close positions, and the reporting scope and timing differ. A volume ratio is not the percentage of a company's float currently held short.
| Time | Action | Open position in this example |
|---|---|---|
| 10:00 | Sell 1,000 shares short | 1,000 shares |
| 11:00 | Buy 1,000 shares to close | 0 shares |
| Later reporting snapshot | No other activity assumed | 0 shares |
Read the coverage before calculating a percentage.
FINRA's daily short-sale files cover publicly disseminated transactions reported through the specified facilities during normal market hours. The consolidated TRF/ADF file concerns covered off-exchange activity; it is not a complete all-venue market total.
If a file shows 40,000 short-sale shares out of 100,000 covered shares, the ratio is 40% within that file's matching coverage. Dividing that numerator by a different provider's all-session or all-venue volume changes the denominator and no longer describes the same ratio.
Keep the filename, session date, facility coverage, and retrieval time with a downloaded observation. Files can be revised. For short interest, preserve the reporting settlement date and publication date rather than relabeling the published snapshot as today's live positioning.
Name the measure.
Position snapshot, transaction volume, or a ratio derived from a matching transaction dataset.
Match the coverage.
Use the same venues, session window, and trade scope for numerator and denominator.
Preserve the dates.
Record when the measurement applies, when it was published, and which file version you read.
Keep the research question tied to the evidence.
When researching a Gapperz scanner result, price and participation can identify an observation worth investigating. A dated short-interest report can add historical position context. Short-sale volume can describe covered transaction activity. Keep those contributions separately labeled.
Read issuer news and share-structure disclosures for additional context, using their own dates and sources. A high activity ratio does not establish manipulation, an unreported position total, or a probability of a squeeze. The useful research note states what the source actually measures.
A few useful answers.
Is short-sale volume the same as short interest?
No. Short-sale volume records qualifying transactions during a period. Short interest records outstanding positions at a reporting snapshot. A short sale that is closed before the snapshot can contribute volume without leaving an open position.
Does 40% short volume mean 40% of float is short?
No. A short-volume percentage uses a transaction-volume denominator within a dataset. Float is a share-supply measure. The ratio does not establish an outstanding short-position count.
Do FINRA's consolidated TRF/ADF short-sale files cover all market trading?
They describe the covered reported activity, including off-exchange transactions through those facilities during the stated hours. They should not be treated as a complete all-venue, all-session market total.
Sources & editorial notes
Prepared by Gapperz using our scanner definitions and the primary references below. The examples are illustrative; the public methodology explains how we label data and research context.