Short interest data,
float ratio and days to cover.

What short interest measures

Short interest is the number of shares that have been sold short and not yet bought back, as of a settlement date. In the U.S., broker-dealers report these positions to FINRA twice a month, and the figures are published after each cycle. Short interest is a stock of open positions, not a flow of trades. Read it alongside the float: 100 million shares short is a lot for a small company and a rounding error for Apple.

The figures come with each company profile refresh, about monthly and sooner after a filing, and the source does not say which settlement date they belong to. settlement_date and published_at are therefore always null: key time series on observed_on, the day OHLC first saw the report. A report is one row, however many times it was observed, and a report published between two refreshes can be missed, so this is not every FINRA cycle.

Reading short interest alongside float

short_float_ratio depends on the float the source used. For your own measure, divide shares_short by float_shares from /v1/share-statistics for the same listing and date, which also lets you apply one float definition across every stock. days_to_cover rises when shorts grow or when trading volume falls, so check both inputs before reading a jump as new bearish conviction. Short interest is reported per listing, keyed by instrument_id, so ticker changes do not split a series.

Short interest is not short volume

Daily short sale volume counts short sales executed on a day, most of which are market-making and closed within hours. It says little about lasting bearish positions. OHLC publishes it separately as short volume: FINRA's daily short sale volume per listing from its reporting facilities, from Massive, each weekday evening. This page covers reported short positions only.

Use cases

• Squeeze screens: high short_float_ratio combined with high days_to_cover.
• Risk monitoring on holdings, flagging names where shorts are building between reports.
• Crowding and positioning factors for quantitative models.
• Context next to institutional ownership and float from /v1/share-statistics.

History and point in time

OHLC began recording short interest in September 2026: on October 3, 2026, Apple's first observation was dated September 22, 2026. History builds forward from there, so this is not yet a multi-year archive. as_of limits results to observations recorded by the end of a UTC day, which keeps a backtest from seeing a figure before OHLC had it.

Plans and credits

Short interest is included on Pro, Commercial and Scale, at 5 credits per symbol or 500 credits for a page across the whole market. Share statistics, including float, are on every plan. See pricing.

curl 'https://api.ohlc.io/v1/short-interest?symbols=XNAS:AAPL&order=desc&limit=1' \
  -H "Authorization: Bearer $OHLC_API_KEY"

{
  "data": [
    {
      "id": "record_f09345b4c876cac242c4",
      "instrument_id": "01M35H2KE2ZJHXFY5C3E7FPC66",
      "settlement_date": null,
      "observed_on": "2026-09-28",
      "published_at": null,
      "shares_short": "128753092",
      "previous_shares_short": "139749097",
      "short_float_ratio": "0.0088",
      "days_to_cover": "3.03"
    }
  ],
  "meta": {
    "timezone": "UTC",
    "as_of": "2026-10-03T15:04:28Z",
    "next_cursor": "AbLIu38MSvRC...",
    "coverage": { "status": "partial", "reason": "Coverage is partial for the entitled query scope." }
  }
}