Level 1 top of book: quoted spread across a full session (AAPL, June 17 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 2026-08-07, from Level 1 vs Level 2 vs Level 3 Market Data.

Rows × columns

32 × 3

Period covered

04:00 to 19:30

Computed

2026-08-07

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

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 2026-08-07, and the query below is what returned them.

SELECT
    formatDateTime(
        toStartOfInterval(toTimeZone(sip_timestamp, 'America/New_York'), INTERVAL 30 MINUTE),
        '%H:%i'
    )                                                                      AS et_time,
    round(avg(toFloat64(ask_price) - toFloat64(bid_price)) * 100, 2)       AS spread_cents,
    round(avg((toFloat64(ask_price) - toFloat64(bid_price))
              / ((toFloat64(ask_price) + toFloat64(bid_price)) / 2)) * 10000, 2) AS spread_bps
FROM global_markets.cache_stocks_quotes
WHERE ticker = 'AAPL'
  AND sip_timestamp >= '2026-06-17 08:00:00'
  AND sip_timestamp <  '2026-06-18 00:00:00'
  AND bid_price > 0
  AND ask_price > bid_price
  AND (toFloat64(ask_price) - toFloat64(bid_price)) / toFloat64(bid_price) < 0.05
GROUP BY et_time
ORDER BY et_time