{"slug":"how-do-market-makers-make-money","qid":"spread_by_time","label":"AAPL average quoted spread by half-hour (ET), one extended session","post_title":"How Do Market Makers Make Money? The Spread","post_url":"/blog/how-do-market-makers-make-money#q-spread_by_time","columns":["et_time","avg_spread_cents"],"rows":[{"et_time":"04:00","avg_spread_cents":33.7},{"et_time":"04:30","avg_spread_cents":29},{"et_time":"05:00","avg_spread_cents":23.7},{"et_time":"05:30","avg_spread_cents":28.7},{"et_time":"06:00","avg_spread_cents":32.1},{"et_time":"06:30","avg_spread_cents":39.3},{"et_time":"07:00","avg_spread_cents":17.6},{"et_time":"07:30","avg_spread_cents":16.1},{"et_time":"08:00","avg_spread_cents":13.4},{"et_time":"08:30","avg_spread_cents":16.1},{"et_time":"09:00","avg_spread_cents":16.6},{"et_time":"09:30","avg_spread_cents":5.7},{"et_time":"10:00","avg_spread_cents":4.1},{"et_time":"10:30","avg_spread_cents":3.5},{"et_time":"11:00","avg_spread_cents":3.1},{"et_time":"11:30","avg_spread_cents":3},{"et_time":"12:00","avg_spread_cents":2.9},{"et_time":"12:30","avg_spread_cents":2.7},{"et_time":"13:00","avg_spread_cents":2.5},{"et_time":"13:30","avg_spread_cents":2.6},{"et_time":"14:00","avg_spread_cents":2.6},{"et_time":"14:30","avg_spread_cents":2.4},{"et_time":"15:00","avg_spread_cents":2.1},{"et_time":"15:30","avg_spread_cents":2.2},{"et_time":"16:00","avg_spread_cents":12.1},{"et_time":"16:30","avg_spread_cents":17.1},{"et_time":"17:00","avg_spread_cents":11.3},{"et_time":"17:30","avg_spread_cents":11.5},{"et_time":"18:00","avg_spread_cents":21.1},{"et_time":"18:30","avg_spread_cents":10.9},{"et_time":"19:00","avg_spread_cents":18.4},{"et_time":"19:30","avg_spread_cents":18.1}],"shape":"series","sql":"WITH (\n  SELECT max(toDate(sip_timestamp))\n  FROM global_markets.cache_stocks_quotes\n  WHERE ticker = 'AAPL' AND sip_timestamp >= now() - INTERVAL 7 DAY\n) AS last_session\nSELECT\n  formatDateTime(toStartOfInterval(toTimeZone(sip_timestamp, 'America/New_York'), INTERVAL 30 MINUTE), '%H:%i') AS et_time,\n  round(avg(ask_price - bid_price) * 100, 1) AS avg_spread_cents\nFROM global_markets.cache_stocks_quotes\nWHERE ticker = 'AAPL'\n  AND sip_timestamp >= now() - INTERVAL 7 DAY\n  AND toDate(sip_timestamp) = last_session\n  AND bid_price > 0 AND ask_price > bid_price\nGROUP BY et_time\nORDER BY et_time","computed_at":"2026-08-22T04:13:27.529668+00:00","elapsed":0.434265585}