Same-session gap fill rate by gap size, eight large caps, 2021 to 2026
Answered against 22 years of US equities and 12 years of US options data and published with the query that produced it. This result is stored as of 2026-08-06, from Do Stock Gaps Always Get Filled? The Data.
| gap_bucket | gap_days | same_session_fill_pct |
|---|---|---|
| 0.25 to 0.5% | 2381 | 74.6 |
| 0.5 to 1% | 2340 | 57.8 |
| 1 to 2% | 1530 | 38.8 |
| 2 to 4% | 526 | 25.1 |
| 4% or more | 135 | 14.8 |
- Rows × columns
- 5 × 3
- Computed
- Completeness
- No missing values
- Source
- US exchange, SIP and OPRA market data
- Licence
- Strasmore terms · free, no signup
What each column holds
| Column | Type | Range | Notes |
|---|---|---|---|
gap_bucket |
text | 5 distinct values (0.25 to 0.5%, 0.5 to 1%, 1 to 2%…) | |
gap_days |
number | 135 to 2,381 | |
same_session_fill_pct |
number | 14.8 to 74.6 | percent |
Computed from Strasmore's warehouse of US exchange, SIP and OPRA market data. Equity prices are delayed; options greeks and implied volatility are end-of-day. This result is stored, not recomputed on load — it is exactly the numbers that were returned on , and the query below is what returned them.
Run it yourself
This is the exact query behind the result above. Change a ticker, a date or a column and run it against the warehouse — no account, no key. The no-signup tier is smaller than the one this page was computed on; a query that reaches past it comes back saying which plan runs it.
WITH sessions AS
(
SELECT
ticker,
toDate(toTimeZone(window_start, 'America/New_York')) AS d,
argMin(toFloat64(open), window_start) AS session_open,
argMax(toFloat64(close), window_start) AS session_close,
toFloat64(max(high)) AS session_high,
toFloat64(min(low)) AS session_low
FROM global_markets.delayed_stocks_minute_aggs
WHERE ticker IN ('AAPL', 'MSFT', 'NVDA', 'AMZN', 'JPM', 'KO', 'WMT', 'XOM')
AND window_start >= '2021-01-01'
AND window_start < '2026-07-01'
AND (toHour(toTimeZone(window_start, 'America/New_York')) * 60
+ toMinute(toTimeZone(window_start, 'America/New_York'))) >= 570
AND (toHour(toTimeZone(window_start, 'America/New_York')) * 60
+ toMinute(toTimeZone(window_start, 'America/New_York'))) < 960
GROUP BY ticker, d
),
gapped AS
(
SELECT
d,
session_open,
session_high,
session_low,
lagInFrame(session_close) OVER (PARTITION BY ticker ORDER BY d ASC
ROWS BETWEEN 1 PRECEDING AND CURRENT ROW) AS prior_close
FROM sessions
),
measured AS
(
SELECT
abs(100 * (session_open / prior_close - 1)) AS gap_pct,
toUInt8(if(session_open > prior_close,
session_low <= prior_close,
session_high >= prior_close)) AS filled_same_session
FROM gapped
WHERE prior_close > 0
AND d <= toDate('2026-02-28')
AND abs(100 * (session_open / prior_close - 1)) >= 0.25
)
SELECT
multiIf(gap_pct < 0.5, '0.25 to 0.5%',
gap_pct < 1, '0.5 to 1%',
gap_pct < 2, '1 to 2%',
gap_pct < 4, '2 to 4%',
'4% or more') AS gap_bucket,
count() AS gap_days,
round(100 * avg(filled_same_session), 1) AS same_session_fill_pct
FROM measured
GROUP BY gap_bucket
ORDER BY min(gap_pct) ASC