{"slug":"what-is-a-bid-ask-spread","qid":"intraday_spread","label":"AAPL median quoted spread by 30-minute bucket (ET, extended hours included)","post_title":"What Is a Bid-Ask Spread? Real Costs","post_url":"/blog/what-is-a-bid-ask-spread#q-intraday_spread","columns":["et_time","median_spread_cents"],"rows":[{"et_time":"04:00","median_spread_cents":27},{"et_time":"04:30","median_spread_cents":15},{"et_time":"05:00","median_spread_cents":16},{"et_time":"05:30","median_spread_cents":19},{"et_time":"06:00","median_spread_cents":21},{"et_time":"06:30","median_spread_cents":26},{"et_time":"07:00","median_spread_cents":15},{"et_time":"07:30","median_spread_cents":13},{"et_time":"08:00","median_spread_cents":14},{"et_time":"08:30","median_spread_cents":13},{"et_time":"09:00","median_spread_cents":15},{"et_time":"09:30","median_spread_cents":4},{"et_time":"10:00","median_spread_cents":3},{"et_time":"10:30","median_spread_cents":3},{"et_time":"11:00","median_spread_cents":3},{"et_time":"11:30","median_spread_cents":2},{"et_time":"12:00","median_spread_cents":2},{"et_time":"12:30","median_spread_cents":2},{"et_time":"13:00","median_spread_cents":2},{"et_time":"13:30","median_spread_cents":2},{"et_time":"14:00","median_spread_cents":2},{"et_time":"14:30","median_spread_cents":2},{"et_time":"15:00","median_spread_cents":2},{"et_time":"15:30","median_spread_cents":2},{"et_time":"16:00","median_spread_cents":10},{"et_time":"16:30","median_spread_cents":10},{"et_time":"17:00","median_spread_cents":9},{"et_time":"17:30","median_spread_cents":10},{"et_time":"18:00","median_spread_cents":17},{"et_time":"18:30","median_spread_cents":9},{"et_time":"19:00","median_spread_cents":17},{"et_time":"19:30","median_spread_cents":11}],"shape":"series","sql":"SELECT formatDateTime(toStartOfInterval(toTimeZone(sip_timestamp, 'America/New_York'), INTERVAL 30 MINUTE), '%H:%i') AS et_time,\n       round(quantileDeterministic(0.5)(toFloat64(ask_price - bid_price), toUInt64(sip_timestamp)) * 100, 1) AS median_spread_cents\nFROM global_markets.cache_stocks_quotes\nWHERE ticker = 'AAPL'\n  AND sip_timestamp >= now() - INTERVAL 7 DAY\n  AND bid_price > 0\n  AND ask_price > bid_price\nGROUP BY et_time\nORDER BY et_time","computed_at":"2026-08-22T04:33:00.717765+00:00","elapsed":0.530482629}