What Is Days to Cover? Short Interest Ratio

Days to cover is short interest divided by average daily trading volume: how many typical days of a stock's entire volume it would take for every short seller to buy back their shares. It also goes by a second name — the short interest ratio — and the two terms mean exactly the same thing. It is the standard gauge of how crowded a short position is relative to the exit, and this page shows how to read it, with real numbers from the latest exchange-reported settlement.

How is days to cover calculated?

Take the reported short interest — every share currently sold short — and divide by the stock's average daily volume. A company with 20 million shares short that trades 10 million shares a day carries 2.0 days to cover. The number is a time estimate by construction: if short sellers had to unwind and absorbed all of the typical day's trading, that is how long the exit would take. Real unwinding never works that cleanly (shorts are a fraction of any day's volume), but the ratio's power is comparative — a name at 10 days is far more crowded than a name at 1, whatever the literal timeline.

Four familiar names from the June 30, 2026 settlement, straight from the exchange-reported record:

SELECT ticker,
       round(short_interest / 1e6, 1) AS shares_short_m,
       round(avg_daily_volume / 1e6, 1) AS avg_daily_volume_m,
       round(days_to_cover, 2) AS days_to_cover
FROM global_markets.stocks_short_interest
WHERE settlement_date = '2026-06-30'
  AND ticker IN ('AAPL', 'GME', 'MU', 'TSLA')
ORDER BY ticker

Look at the shape, not just the levels. AAPL carries 140.5 million shares short — more than double GME's 55.9 million — yet its days to cover is only 1.73: at 81.1 million shares of daily volume, that short position is a rounding error of the tape. GME shows the reverse: a smaller absolute position over thin volume puts it at 10.75 days to cover — the famous name of the 2021 short squeeze is once again the crowded one. This is the whole point of the ratio: raw short interest counts shares, days to cover counts exit time.

What counts as high days to cover?

Calibrate against the actual market. Across every liquid name (5M+ shares of average daily volume) at the June 30 settlement:

SELECT multiIf(days_to_cover <= 1, '1 (the reported floor)',
               days_to_cover < 2, '>1 to 2 days',
               days_to_cover < 5, '2 to 5 days',
               days_to_cover < 10, '5 to 10 days',
               '10+ days') AS bucket,
       count() AS names
FROM global_markets.stocks_short_interest
WHERE settlement_date = '2026-06-30'
  AND avg_daily_volume >= 5000000
  AND days_to_cover IS NOT NULL
GROUP BY bucket
ORDER BY min(days_to_cover)

The mass sits low: 323 names at the floor and 188 between one and two days, thinning fast to just 5 names at ten days or more. In this tape, anything above five days is uncommon and double digits is rare air. One data note worth knowing before you compare sources:

SELECT round(min(days_to_cover), 2) AS minimum_reported,
       countIf(days_to_cover = 1) AS names_reported_at_1,
       count() AS liquid_names
FROM global_markets.stocks_short_interest
WHERE settlement_date = '2026-06-30'
  AND avg_daily_volume >= 5000000
  AND days_to_cover IS NOT NULL

The minimum reported value across all 947 liquid names is 1 — the feed floors the ratio at one day, and 323 names sit exactly there. A mega-cap whose true arithmetic works out to half a day still prints 1.0, so treat "1" as "one day or less," and don't read differences below the floor into the data.

Both halves of the fraction move

The subtlety most explainers skip: days to cover has a numerator and a denominator, and the denominator is the twitchy one. A burst of trading volume — an earnings week, an index add, a viral day — can cut a stock's days to cover in half while not a single short seller closes a position. The reverse holds too: volume drying up inflates the ratio with no new shorting. GME's own history is the textbook: at the November 13, 2020 settlement it reported 14 days to cover; by January 29, 2021 — mid-squeeze, with volume exploding — it printed 1, even while tens of millions of shares remained short.

SELECT round(anyIf(days_to_cover, settlement_date = '2020-11-13'), 1) AS nov_2020_days_to_cover,
       round(anyIf(days_to_cover, settlement_date = '2021-01-29'), 1) AS jan_2021_days_to_cover,
       round(anyIf(short_interest, settlement_date = '2021-01-29') / 1e6, 1) AS jan_2021_shares_short_m
FROM global_markets.stocks_short_interest
WHERE ticker = 'GME'
  AND settlement_date IN ('2020-11-13', '2021-01-29')

Days to cover also gets confused with a different crowding measure: short interest as a percent of float, which divides shares short by the tradable share count instead of by daily volume. The two answer different questions — percent-of-float measures how much of the ownership pie is sold short; days to cover measures how narrow the exit door is. A heavily shorted stock that trades enormous volume can carry a low days to cover, and a modestly shorted stock in a sleepy tape can carry a high one. Screens built on one will rank names differently than screens built on the other, which is worth knowing before comparing lists across websites.

So read the ratio with its date and its volume context, never alone. And read it with its lag: short interest is exchange-reported only twice a month on a delayed schedule — why short interest is two weeks old documents the exact cadence, and short interest vs short volume covers the daily-flavored metric people confuse it with.

Days to cover FAQ

What is a good or high days to cover?

There is no official threshold, but the market's own distribution is a guide: at the June 30, 2026 settlement, most liquid names sat at two days or less, only 5 liquid names reached ten-plus, and five-plus was already uncommon. Traders watching for squeeze conditions typically treat high single digits and up as crowded.

Is days to cover the same as the short interest ratio?

Yes — "days to cover" and "short interest ratio" are two names for the same calculation: short interest divided by average daily volume. Some sources abbreviate it SIR.

How is days to cover calculated?

Reported short interest ÷ average daily trading volume. Both inputs come from the exchange-reported short interest file, published twice monthly on a lag; the volume denominator is the average over a recent window, so the ratio moves when either shares short or trading volume changes.

Can days to cover fall without short sellers covering?

Yes, and it happens constantly: a volume spike grows the denominator and shrinks the ratio with zero change in the short position. GME printed 1 days to cover at the January 29, 2021 settlement with 21.4 million shares still short — the squeeze's enormous volume, not a completed unwind, drove the ratio down.

Every figure above is a stored, versioned query over the exchange-reported short interest file — expand any panel's SQL, or pull days to cover for your own watchlist on the Strasmore terminal.