{"slug":"reg-t-margin-vs-portfolio-margin","qid":"skew_curve","label":"Average implied volatility by strike distance from spot, SPY, May to June 2026","post_title":"Reg T Margin vs Portfolio Margin Explained","post_url":"/blog/reg-t-margin-vs-portfolio-margin#q-skew_curve","columns":["strike_vs_spot","avg_iv_pct","contract_volume"],"rows":[{"strike_vs_spot":"-20%","avg_iv_pct":36.7,"contract_volume":215010},{"strike_vs_spot":"-15%","avg_iv_pct":31.1,"contract_volume":549607},{"strike_vs_spot":"-10%","avg_iv_pct":25,"contract_volume":1344752},{"strike_vs_spot":"-5%","avg_iv_pct":19.4,"contract_volume":5994700},{"strike_vs_spot":"0%","avg_iv_pct":15.2,"contract_volume":5856394},{"strike_vs_spot":"+5%","avg_iv_pct":12.8,"contract_volume":1932248},{"strike_vs_spot":"+10%","avg_iv_pct":13.8,"contract_volume":270654},{"strike_vs_spot":"+15%","avg_iv_pct":16.9,"contract_volume":160736},{"strike_vs_spot":"+20%","avg_iv_pct":20.1,"contract_volume":90329}],"shape":"ranking","sql":"SELECT\n    concat(if(step > 0, '+', ''), toString(step), '%') AS strike_vs_spot,\n    round(avg(implied_volatility) * 100, 1)            AS avg_iv_pct,\n    sum(volume)                                        AS contract_volume\nFROM\n(\n    SELECT\n        implied_volatility,\n        volume,\n        toInt32(round((toFloat64(strike_price) / toFloat64(underlying_close) - 1) * 20)) * 5 AS step\n    FROM global_markets.options_greeks\n    WHERE underlying_symbol = 'SPY'\n      AND date >= '2026-05-01'\n      AND date <  '2026-07-01'\n      AND iv_converged = 1\n      AND volume > 0\n      AND days_to_expiry BETWEEN 20 AND 45\n      AND underlying_close > 0\n      AND abs(toFloat64(strike_price) / toFloat64(underlying_close) - 1) <= 0.205\n)\nGROUP BY step\nORDER BY step","computed_at":"2026-08-09T15:41:49.497964+00:00","elapsed":0.003359542}