STRASMORE/EXPLORE 2,170 QUERIES

SPY's median spread ranked against every July session, tightest first

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 2026-08-01, from Market Recap: July 29, 2026, The Day in Numbers.

as of scalar 1×4read in context →
jul29 median spread bps
0.27
rank tightest
20
sessions compared
20
first session
2026-07-01
Rows × columns
1 × 4
Period covered
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 SPY's median spread ranked against every July session, tightest first, derived from the stored result.
ColumnTypeRangeNotes
jul29_median_spread_bps number every row is 0.27
rank_tightest number every row is 20
sessions_compared number every row is 20
first_session date 2026-07-01

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 round(anyIf(spread_bps, d = toDate('2026-07-29')), 2) AS jul29_median_spread_bps,
       arrayCount(x -> x < anyIf(spread_bps, d = toDate('2026-07-29')), groupArrayIf(spread_bps, d != toDate('2026-07-29'))) + 1 AS rank_tightest,
       count() AS sessions_compared,
       toString(min(d)) AS first_session
FROM (
    SELECT toDate(sip_timestamp) AS d,
           quantileExactIf(0.5)(10000 * (toFloat64(ask_price) - toFloat64(bid_price)) / ((toFloat64(ask_price) + toFloat64(bid_price)) / 2), bid_price > 0 AND ask_price > 0 AND ask_price >= bid_price) AS spread_bps
    FROM global_markets.cache_stocks_quotes
    WHERE ticker = 'SPY'
      AND sip_timestamp >= '2026-07-01 13:30:00' AND sip_timestamp < '2026-07-29 20:00:00'
      AND (toHour(sip_timestamp) * 60 + toMinute(sip_timestamp)) BETWEEN 810 AND 1199
    GROUP BY d
    HAVING countIf(bid_price > 0 AND ask_price > 0 AND ask_price >= bid_price) > 0
)

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