STRASMORE/EXPLORE 2,170 QUERIES

Month-end sessions vs all other sessions: SPY close concentration, January–June 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 2026-07-26, from When Do Mutual Funds Trade? NAV Pricing at 4 pm.

as of scalar 1×7read in context →
month end sessions
6
other sessions
117
month end final half pct
25.1
other final half pct
18.3
gap pp
6.9
month end final min pct
5.2
other final min pct
3.2
Rows × columns
1 × 7
Computed
Completeness
No missing values
Source
US exchange, SIP and OPRA market data
Licence
Strasmore terms · free, no signup
Formats
JSON · CSV · the SQL below

What each column holds

Column definitions for Month-end sessions vs all other sessions: SPY close concentration, January–June 2026, derived from the stored result.
ColumnTypeRangeNotes
month_end_sessions number every row is 6
other_sessions number every row is 117
month_end_final_half_pct number every row is 25.1 percent
other_final_half_pct number every row is 18.3 percent
gap_pp number every row is 6.9
month_end_final_min_pct number every row is 5.2 percent
other_final_min_pct number every row is 3.2 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.

the exact SQL behind every number 
SELECT
    countIf(is_month_end) AS month_end_sessions,
    countIf(NOT is_month_end) AS other_sessions,
    round(avgIf(final_half_hour_pct, is_month_end), 1) AS month_end_final_half_pct,
    round(avgIf(final_half_hour_pct, NOT is_month_end), 1) AS other_final_half_pct,
    round(avgIf(final_half_hour_pct, is_month_end) - avgIf(final_half_hour_pct, NOT is_month_end), 1) AS gap_pp,
    round(avgIf(final_minute_pct, is_month_end), 1) AS month_end_final_min_pct,
    round(avgIf(final_minute_pct, NOT is_month_end), 1) AS other_final_min_pct
FROM (
    SELECT
        session_date,
        final_half_hour_pct,
        final_minute_pct,
        session_date = max(session_date) OVER (PARTITION BY toStartOfMonth(session_date)) AS is_month_end
    FROM (
        SELECT
            toDate(toTimeZone(window_start, 'America/New_York')) AS session_date,
            100.0 * sumIf(toFloat64(volume), formatDateTime(toTimeZone(window_start, 'America/New_York'), '%H:%i') >= '15:30') / sum(toFloat64(volume)) AS final_half_hour_pct,
            100.0 * sumIf(toFloat64(volume), formatDateTime(toTimeZone(window_start, 'America/New_York'), '%H:%i') = '15:59') / sum(toFloat64(volume)) AS final_minute_pct
        FROM global_markets.delayed_stocks_minute_aggs
        WHERE ticker = 'SPY'
          AND toDate(toTimeZone(window_start, 'America/New_York')) >= '2026-01-01'
          AND toDate(toTimeZone(window_start, 'America/New_York')) < '2026-07-01'
          AND formatDateTime(toTimeZone(window_start, 'America/New_York'), '%H:%i') BETWEEN '09:30' AND '15:59'
        GROUP BY session_date
    )
)

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 analysisWhen Do Mutual Funds Trade? NAV Pricing at 4 pm
The same 15 sessions, summarized: the close's floor, average, and peak scalar 1×4 → How much of SPY's day trades at the very end: July 10, 2026 regular session scalar 1×3 → The print NAV is struck from: AAPL's closing auction cross, July 10, 2026 scalar 1×6 → SPY volume share of the final 30 minutes and final minute: last 15 sessions through July 10, 2026 series 15×3 → The spread a fund buyer never pays: median quoted spread, July 10, 2026 regular session ranking 3×3 → One session, many prices: VOO in half-hour marks, Wednesday July 22, 2026 series 32×3 → See all 2,170 queries →