Reg T Margin vs Portfolio Margin Explained
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The LEAPS call's delta climbing toward 1 as it goes deep in the moneyseries ·
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Buying and Selling Call Options
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SPY realized volatility and worst session, by calendar year
SPY realized volatility and worst session, by calendar year
| year | realized_vol_pct | worst_day_pct | days_over_2pct_count |
|---|---|---|---|
| 2007 | 15.9 | -3.9 | 14 |
| 2008 | 41.2 | -9.8 | 70 |
| 2009 | 26.6 | -5.3 | 50 |
| 2010 | 17.9 | -3.8 | 22 |
| 2011 | 23 | -6.5 | 33 |
| 2012 | 12.8 | -2.5 | 7 |
| 2013 | 11.1 | -2.5 | 4 |
| 2014 | 11.3 | -2.3 | 4 |
| 2015 | 15.5 | -4.2 | 11 |
| 2016 | 13.1 | -3.6 | 10 |
| 2017 | 6.8 | -1.8 | 0 |
| 2018 | 17.1 | -4.2 | 19 |
| 2019 | 12.5 | -3 | 7 |
| 2020 | 33.4 | -10.9 | 42 |
| 2021 | 13.1 | -2.4 | 8 |
| 2022 | 24.2 | -4.3 | 46 |
| 2023 | 13.2 | -2 | 2 |
| 2024 | 12.6 | -3 | 7 |
| 2025 | 19.4 | -5.9 | 14 |
| 2026 | 14.2 | -2.6 | 4 |
the exact SQL behind every number
SELECT
toYear(session_date) AS year,
round(stddevPop(daily_pct) * sqrt(252), 1) AS realized_vol_pct,
round(min(daily_pct), 1) AS worst_day_pct,
countIf(abs(daily_pct) >= 2) AS days_over_2pct_count
FROM
(
SELECT
date AS session_date,
(toFloat64(close) / lagInFrame(toFloat64(close), 1) OVER (ORDER BY date ROWS BETWEEN 1 PRECEDING AND CURRENT ROW) - 1) * 100 AS daily_pct
FROM global_markets.stocks_daily_aggs
WHERE ticker = 'SPY'
AND date >= '2007-01-01'
AND date < '2026-07-01'
)
WHERE isFinite(daily_pct)
GROUP BY year
ORDER BY year
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