{"slug":"price-time-priority-vs-pro-rata","qid":"quote_churn","label":"Quote updates per second and average quoted spread, ten minutes on 17 June 2026","post_title":"Price-Time Priority vs Pro-Rata Fills","post_url":"/blog/price-time-priority-vs-pro-rata#q-quote_churn","columns":["symbol","quote_updates_per_second","avg_spread_bps"],"rows":[{"symbol":"SPY","quote_updates_per_second":296.4,"avg_spread_bps":0.32},{"symbol":"NVDA","quote_updates_per_second":181.1,"avg_spread_bps":1.25},{"symbol":"AAPL","quote_updates_per_second":34.4,"avg_spread_bps":1.51},{"symbol":"MSFT","quote_updates_per_second":29.5,"avg_spread_bps":2.16},{"symbol":"KO","quote_updates_per_second":28.8,"avg_spread_bps":2.27}],"shape":"ranking","sql":"SELECT\n    ticker                    AS symbol,\n    round(count() / 600.0, 1) AS quote_updates_per_second,\n    round(avg(toFloat64(ask_price) - toFloat64(bid_price))\n          / avg(toFloat64(bid_price)) * 10000, 2) AS avg_spread_bps\nFROM global_markets.cache_stocks_quotes\nWHERE ticker IN ('AAPL', 'MSFT', 'NVDA', 'SPY', 'KO')\n  AND sip_timestamp >= '2026-06-17 14:00:00'\n  AND sip_timestamp <  '2026-06-17 14:10:00'\n  AND bid_price > 0\n  AND ask_price > bid_price\nGROUP BY ticker\nORDER BY quote_updates_per_second DESC","computed_at":"2026-08-08T15:20:56.109172+00:00","elapsed":0.002738308}