AAPL median quoted spread by 30-minute bucket (ET, extended hours included)
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 2026-08-22, from What Is a Bid-Ask Spread? Real Costs.
| et_time | median_spread_cents |
|---|---|
| 04:00 | 27 |
| 04:30 | 15 |
| 05:00 | 16 |
| 05:30 | 19 |
| 06:00 | 21 |
| 06:30 | 26 |
| 07:00 | 15 |
| 07:30 | 13 |
| 08:00 | 14 |
| 08:30 | 13 |
| 09:00 | 15 |
| 09:30 | 4 |
| 10:00 | 3 |
| 10:30 | 3 |
| 11:00 | 3 |
| 11:30 | 2 |
| 12:00 | 2 |
| 12:30 | 2 |
| 13:00 | 2 |
| 13:30 | 2 |
| 14:00 | 2 |
| 14:30 | 2 |
| 15:00 | 2 |
| 15:30 | 2 |
| 16:00 | 10 |
| 16:30 | 10 |
| 17:00 | 9 |
| 17:30 | 10 |
| 18:00 | 17 |
| 18:30 | 9 |
| 19:00 | 17 |
| 19:30 | 11 |
- Rows × columns
- 32 × 2
- 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 |
|---|---|---|---|
et_time |
date | 04:00 to 19:30 | |
median_spread_cents |
number | 2 to 27 |
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 formatDateTime(toStartOfInterval(toTimeZone(sip_timestamp, 'America/New_York'), INTERVAL 30 MINUTE), '%H:%i') AS et_time,
round(quantileDeterministic(0.5)(toFloat64(ask_price - bid_price), toUInt64(sip_timestamp)) * 100, 1) AS median_spread_cents
FROM global_markets.cache_stocks_quotes
WHERE ticker = 'AAPL'
AND sip_timestamp >= now() - INTERVAL 7 DAY
AND bid_price > 0
AND ask_price > bid_price
GROUP BY et_time
ORDER BY et_time
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