Prior close to expiration-Friday open, monthly expirations (SPY, percent)
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 2026-10-24, from When Do SPX Options Stop Trading?.
| expiration_date | expiration_label | overnight_gap_pct | abs_gap_pct | avg_abs_gap_pct |
|---|---|---|---|---|
| 2025-10-17 | Oct 17, 2025 | -0.17 | 0.17 | 0.42 |
| 2025-11-21 | Nov 21, 2025 | 0.39 | 0.39 | 0.42 |
| 2025-12-19 | Dec 19, 2025 | 0.02 | 0.02 | 0.42 |
| 2026-01-16 | Jan 16, 2026 | 0.21 | 0.21 | 0.42 |
| 2026-02-20 | Feb 20, 2026 | -0.32 | 0.32 | 0.42 |
| 2026-03-20 | Mar 20, 2026 | -0.5 | 0.5 | 0.42 |
| 2026-04-17 | Apr 17, 2026 | 0.64 | 0.64 | 0.42 |
| 2026-05-15 | May 15, 2026 | -0.85 | 0.85 | 0.42 |
| 2026-07-17 | Jul 17, 2026 | -1.15 | 1.15 | 0.42 |
| 2026-08-21 | Aug 21, 2026 | 0.45 | 0.45 | 0.42 |
| 2026-09-18 | Sep 18, 2026 | -0.17 | 0.17 | 0.42 |
| 2026-10-16 | Oct 16, 2026 | 0.19 | 0.19 | 0.42 |
- Rows × columns
- 12 × 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 |
|---|---|---|---|
expiration_date |
date | 2025-10-17 to 2026-10-16 | |
expiration_label |
text | 12 distinct values (Apr 17, 2026, Aug 21, 2026, Dec 19, 2025…) | |
overnight_gap_pct |
number | -1.15 to 0.64 | percent |
abs_gap_pct |
number | 0.02 to 1.15 | percent |
avg_abs_gap_pct |
number | every row is 0.42 | 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.
SELECT
toString(d) AS expiration_date,
formatDateTime(d, '%b %e, %Y') AS expiration_label,
round(gap_pct, 2) AS overnight_gap_pct,
round(abs(gap_pct), 2) AS abs_gap_pct,
round(avg(abs(gap_pct)) OVER (), 2) AS avg_abs_gap_pct
FROM
(
SELECT
d,
100 * (toFloat64(open_px) - toFloat64(prev_close)) / toFloat64(prev_close) AS gap_pct
FROM
(
SELECT
date AS d,
open AS open_px,
lagInFrame(close) OVER (ORDER BY date ASC) AS prev_close
FROM global_markets.stocks_daily_aggs
WHERE ticker = 'SPY'
AND date >= '2025-10-01'
AND date <= today() - 2
)
WHERE toDayOfWeek(d) = 5
AND toDayOfMonth(d) BETWEEN 15 AND 21
)
ORDER BY expiration_date
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