{"slug":"when-does-a-stock-split-take-effect","qid":"effective_weekday","label":"Effective dates by weekday: US-listed splits, 2021 to mid-2026","post_title":"When Does a Stock Split Take Effect?","post_url":"/blog/when-does-a-stock-split-take-effect#q-effective_weekday","columns":["weekday","forward_splits","reverse_splits"],"rows":[{"weekday":"Thursday","forward_splits":300,"reverse_splits":789},{"weekday":"Monday","forward_splits":267,"reverse_splits":1162},{"weekday":"Friday","forward_splits":229,"reverse_splits":975},{"weekday":"Tuesday","forward_splits":199,"reverse_splits":922},{"weekday":"Wednesday","forward_splits":183,"reverse_splits":709}],"shape":"series","sql":"WITH s AS (\n    SELECT ticker,\n           execution_date,\n           toFloat64(max(split_to)) / toFloat64(max(split_from)) AS ratio\n    FROM global_markets.stocks_splits\n    WHERE execution_date >= toDate('2021-01-01')\n      AND execution_date <= toDate('2026-07-31')\n      AND split_to > 0\n      AND split_from > 0\n    GROUP BY ticker, execution_date\n)\nSELECT multiIf(toDayOfWeek(execution_date) = 1, 'Monday',\n               toDayOfWeek(execution_date) = 2, 'Tuesday',\n               toDayOfWeek(execution_date) = 3, 'Wednesday',\n               toDayOfWeek(execution_date) = 4, 'Thursday',\n               'Friday') AS weekday,\n       countIf(ratio >= 1.25) AS forward_splits,\n       countIf(ratio < 1) AS reverse_splits\nFROM s\nWHERE toDayOfWeek(execution_date) <= 5\nGROUP BY weekday\nORDER BY forward_splits DESC, weekday","computed_at":"2026-08-05T04:35:35.543130+00:00","elapsed":0.002875999}