Overnight gaps by ticker, H1 2026: average absolute gap and the single biggest gap
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 2026-07-26, from Why Do Stocks Gap Up or Down Overnight?.
| ticker | sessions | avg_abs_gap_pct | biggest_gap_pct | biggest_gap_day |
|---|---|---|---|---|
| SPY | 123 | 0.45 | 2.6 | April 8, 2026 |
| KO | 123 | 0.42 | 5.41 | April 28, 2026 |
| AAPL | 123 | 0.53 | 2.82 | May 1, 2026 |
| MSFT | 123 | 0.89 | -8.66 | January 29, 2026 |
| NVDA | 123 | 0.99 | 3.6 | April 8, 2026 |
| TSLA | 123 | 1.05 | 4.97 | April 8, 2026 |
- Rows × columns
- 6 × 5
- Period covered
- to
- 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 |
|---|---|---|---|
ticker |
text | 6 distinct values (AAPL, KO, MSFT…) | |
sessions |
number | every row is 123 | |
avg_abs_gap_pct |
number | 0.42 to 1.05 | percent |
biggest_gap_pct |
number | -8.66 to 5.41 | percent |
biggest_gap_day |
date | April 28, to May 1, 202 |
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.
the exact SQL behind every number
SELECT ticker,
count() AS sessions,
round(avg(abs(gap_pct)), 2) AS avg_abs_gap_pct,
round(argMax(gap_pct, (abs(gap_pct), day)), 2) AS biggest_gap_pct,
concat(monthName(argMax(day, (abs(gap_pct), day))), ' ', toString(toDayOfMonth(argMax(day, (abs(gap_pct), day)))), ', ', toString(toYear(argMax(day, (abs(gap_pct), day))))) AS biggest_gap_day
FROM (
SELECT ticker, day, 100 * (rth_open - prior_close) / prior_close AS gap_pct
FROM (
SELECT ticker, day, rth_open,
lagInFrame(rth_close) OVER (PARTITION BY ticker ORDER BY day) AS prior_close
FROM (
SELECT ticker, toDate(toTimeZone(window_start, 'America/New_York')) AS day,
argMinIf(toFloat64(open), window_start, rth) AS rth_open,
argMaxIf(toFloat64(close), window_start, rth) AS rth_close
FROM (
SELECT ticker, window_start, open, close,
toTimeZone(window_start, 'America/New_York') >= toDateTime(concat(toString(toDate(toTimeZone(window_start, 'America/New_York'))), ' 09:30:00'), 'America/New_York')
AND toTimeZone(window_start, 'America/New_York') < toDateTime(concat(toString(toDate(toTimeZone(window_start, 'America/New_York'))), ' 16:00:00'), 'America/New_York') AS rth
FROM global_markets.delayed_stocks_minute_aggs
WHERE ticker IN ('SPY', 'KO', 'AAPL', 'MSFT', 'NVDA', 'TSLA')
AND window_start >= '2025-12-29 04:00:00'
AND window_start < '2026-07-01 08:00:00'
)
GROUP BY ticker, day
)
)
WHERE day >= '2026-01-01' AND prior_close > 0 AND isFinite(prior_close)
)
GROUP BY ticker
ORDER BY indexOf(['SPY', 'KO', 'AAPL', 'MSFT', 'NVDA', 'TSLA'], ticker)
Run your own version of this
The same 22 years of US equities and 12 years of options data are queryable in SQL or plain English. A free account runs 100 queries a day and takes no card.
More from this analysisWhy Do Stocks Gap Up or Down Overnight?
MSFT: how the January 29, 2026 gap formed, 30-minute premarket buckets
series 11×8
→
SPY's six biggest overnight gaps of H1 2026: and the same day's open-to-close move
series 6×3
→
SPY overnight gaps by weekday: every session, January 2024 through June 2026
series 5×4
→
MSFT straddle prices at the close before the gap: Jan 28, 2026, Jan 30 expiry
table 4×5
→
What crossed the wire during SPY's biggest overnight gap of H1 2026
table 2×3
→
SPY, H1 2026: average absolute overnight gap vs average absolute intraday move
scalar 1×4
→
See all 2,170 queries →