{"slug":"what-is-sq-day-japan-options","qid":"open_share_by_month","label":"Share of SPY session volume printed in the opening minute, third Friday vs other Fridays","post_title":"When Is SQ Day for Nikkei 225 Options?","post_url":"/blog/what-is-sq-day-japan-options#q-open_share_by_month","columns":["month","month_label","third_friday_pct","other_friday_pct"],"rows":[{"month":"2025-08-01","month_label":"Aug 2025","third_friday_pct":1.33,"other_friday_pct":0.95},{"month":"2025-09-01","month_label":"Sep 2025","third_friday_pct":1.89,"other_friday_pct":1.07},{"month":"2025-10-01","month_label":"Oct 2025","third_friday_pct":1.7,"other_friday_pct":0.92},{"month":"2025-11-01","month_label":"Nov 2025","third_friday_pct":1.14,"other_friday_pct":1.44},{"month":"2025-12-01","month_label":"Dec 2025","third_friday_pct":1.26,"other_friday_pct":1.23},{"month":"2026-01-01","month_label":"Jan 2026","third_friday_pct":1.31,"other_friday_pct":1.31},{"month":"2026-02-01","month_label":"Feb 2026","third_friday_pct":0.81,"other_friday_pct":1.34},{"month":"2026-03-01","month_label":"Mar 2026","third_friday_pct":0.6,"other_friday_pct":0.96},{"month":"2026-04-01","month_label":"Apr 2026","third_friday_pct":1.45,"other_friday_pct":1.71},{"month":"2026-05-01","month_label":"May 2026","third_friday_pct":1.44,"other_friday_pct":1.25},{"month":"2026-07-01","month_label":"Jul 2026","third_friday_pct":1.67,"other_friday_pct":1.13}],"shape":"series","sql":"WITH per_session AS\n(\n    SELECT\n        toDate(toTimeZone(window_start, 'America/New_York'))            AS session_date,\n        sumIf(toFloat64(volume), et_minute = 570)                       AS opening_minute_volume,\n        sumIf(toFloat64(volume), et_minute >= 570 AND et_minute < 960)  AS session_volume,\n        countIf(et_minute >= 570 AND et_minute < 960)                   AS session_minutes\n    FROM\n    (\n        SELECT\n            window_start,\n            volume,\n            toHour(toTimeZone(window_start, 'America/New_York')) * 60\n              + toMinute(toTimeZone(window_start, 'America/New_York'))  AS et_minute\n        FROM global_markets.delayed_stocks_minute_aggs\n        WHERE ticker = 'SPY'\n          AND window_start >= '2025-08-01'\n          AND window_start <  '2026-08-01'\n    )\n    GROUP BY session_date\n    HAVING session_volume > 0 AND session_minutes > 300\n)\nSELECT\n    toString(toStartOfMonth(session_date))                     AS month,\n    formatDateTime(toStartOfMonth(session_date), '%b %Y')      AS month_label,\n    round(100 * avgIf(opening_minute_volume / session_volume,\n                      toDayOfMonth(session_date) BETWEEN 15 AND 21), 2)      AS third_friday_pct,\n    round(100 * avgIf(opening_minute_volume / session_volume,\n                      toDayOfMonth(session_date) NOT BETWEEN 15 AND 21), 2)  AS other_friday_pct\nFROM per_session\nWHERE toDayOfWeek(session_date) = 5\nGROUP BY month, month_label\nHAVING countIf(toDayOfMonth(session_date) BETWEEN 15 AND 21) > 0\n   AND countIf(toDayOfMonth(session_date) NOT BETWEEN 15 AND 21) > 0\nORDER BY month","computed_at":"2026-08-16T14:09:47.516843+00:00","elapsed":0.004323986}