{"slug":"when-do-index-funds-trade","qid":"spread_cost","label":"spread_cost","post_title":"when-do-index-funds-trade","post_url":"/blog/when-do-index-funds-trade#q-spread_cost","columns":["symbol","avg_spread_bps","p90_spread_bps"],"rows":[{"symbol":"SPY","avg_spread_bps":0.273,"p90_spread_bps":0.395},{"symbol":"QQQ","avg_spread_bps":0.332,"p90_spread_bps":0.423},{"symbol":"VOO","avg_spread_bps":0.428,"p90_spread_bps":0.573},{"symbol":"IWM","avg_spread_bps":0.471,"p90_spread_bps":0.7},{"symbol":"IVV","avg_spread_bps":0.739,"p90_spread_bps":0.92},{"symbol":"DIA","avg_spread_bps":0.798,"p90_spread_bps":0.96}],"shape":"ranking","sql":"SELECT\n    ticker                                                                                                                                        AS symbol,\n    round(avg(20000 * toFloat64(ask_price - bid_price) / toFloat64(ask_price + bid_price)), 3)                                                     AS avg_spread_bps,\n    round(quantileDeterministic(0.9)(20000 * toFloat64(ask_price - bid_price) / toFloat64(ask_price + bid_price), toUInt64(sequence_number)), 3)    AS p90_spread_bps\nFROM global_markets.cache_stocks_quotes\nWHERE ticker IN ('SPY', 'VOO', 'IVV', 'QQQ', 'DIA', 'IWM')\n  AND sip_timestamp >= toDateTime('2026-09-15 14:00:00')\n  AND sip_timestamp <  toDateTime('2026-09-15 14:05:00')\n  AND ask_price > bid_price\n  AND bid_price > 0\nGROUP BY ticker\nORDER BY avg_spread_bps","computed_at":"2026-09-26T15:12:29.573783+00:00","elapsed":0.03520446}