{"slug":"what-is-backtesting","qid":"close_to_next_open","label":"Distance from one close to the next open, liquid names, 2025 (basis points)","post_title":"What Is Backtesting in Trading?","post_url":"/blog/what-is-backtesting#q-close_to_next_open","columns":["ticker","avg_abs_gap_bps","median_abs_gap_bps"],"rows":[{"ticker":"AAPL","avg_abs_gap_bps":73.3,"median_abs_gap_bps":36.4},{"ticker":"MSFT","avg_abs_gap_bps":66.3,"median_abs_gap_bps":39.8},{"ticker":"TLT","avg_abs_gap_bps":47.1,"median_abs_gap_bps":37.5},{"ticker":"SPY","avg_abs_gap_bps":46.7,"median_abs_gap_bps":28.5},{"ticker":"KO","avg_abs_gap_bps":38.1,"median_abs_gap_bps":23.5}],"shape":"ranking","sql":"WITH\n    px AS\n    (\n        SELECT\n            ticker,\n            date,\n            toFloat64(open)  AS open_px,\n            toFloat64(close) AS close_px\n        FROM global_markets.stocks_daily_aggs\n        WHERE ticker IN ('SPY', 'AAPL', 'MSFT', 'KO', 'TLT')\n          AND date >= '2025-01-01'\n          AND date <= '2025-12-31'\n    ),\n    gaps AS\n    (\n        SELECT\n            ticker,\n            date,\n            close_px,\n            leadInFrame(open_px) OVER (PARTITION BY ticker ORDER BY date ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING) AS next_open\n        FROM px\n    )\nSELECT\n    ticker,\n    round(avg(abs(next_open / close_px - 1)) * 10000, 1)     AS avg_abs_gap_bps,\n    round(median(abs(next_open / close_px - 1)) * 10000, 1)  AS median_abs_gap_bps\nFROM gaps\nWHERE next_open > 0\nGROUP BY ticker\nORDER BY avg_abs_gap_bps DESC, ticker ASC","computed_at":"2026-09-16T14:47:26.454191+00:00","elapsed":0.003204874}