{"slug":"paper-trading-before-real-money","qid":"spread_by_clock","label":"One session shape: median quoted spread by half-hour bucket, Ford (F), recent completed sessions","post_title":"Paper Trading Before Real Money","post_url":"/blog/paper-trading-before-real-money#q-spread_by_clock","columns":["et_time","spread_bps","quote_updates_m"],"rows":[{"et_time":"09:30","spread_bps":7.16,"quote_updates_m":0.06},{"et_time":"10:00","spread_bps":7.15,"quote_updates_m":0.07},{"et_time":"10:30","spread_bps":7.16,"quote_updates_m":0.04},{"et_time":"11:00","spread_bps":7.19,"quote_updates_m":0.04},{"et_time":"11:30","spread_bps":7.19,"quote_updates_m":0.03},{"et_time":"12:00","spread_bps":7.08,"quote_updates_m":0.02},{"et_time":"12:30","spread_bps":7.06,"quote_updates_m":0.02},{"et_time":"13:00","spread_bps":7.18,"quote_updates_m":0.02},{"et_time":"13:30","spread_bps":7.19,"quote_updates_m":0.02},{"et_time":"14:00","spread_bps":7.08,"quote_updates_m":0.03},{"et_time":"14:30","spread_bps":7.1,"quote_updates_m":0.02},{"et_time":"15:00","spread_bps":7.14,"quote_updates_m":0.03},{"et_time":"15:30","spread_bps":7.16,"quote_updates_m":0.05}],"shape":"series","sql":"SELECT formatDateTime(toStartOfInterval(toTimeZone(sip_timestamp, 'America/New_York'), INTERVAL 30 MINUTE), '%H:%i') AS et_time,\n       round(quantileExactIf(0.5)(toFloat64(ask_price - bid_price) / (toFloat64(ask_price + bid_price) / 2), bid_price > 0 AND ask_price > bid_price) * 10000, 2) AS spread_bps,\n       round(count() / 1e6, 2) AS quote_updates_m\nFROM global_markets.cache_stocks_quotes\nWHERE ticker = 'F'\n  AND sip_timestamp >= toDateTime(today() - 10)\n  AND sip_timestamp < toDateTime(today() - 3)\n  AND (toHour(sip_timestamp) * 60 + toMinute(sip_timestamp)) BETWEEN 810 AND 1199\nGROUP BY et_time\nORDER BY et_time","computed_at":"2026-08-22T04:18:08.410650+00:00","elapsed":0.149556296}