CBOE S&P 500 9-Day Volatility Index GARCH Volatility Analysis
Volatility prediction for Tuesday, July 21st, 2026
1 Day
219.39%
decreased by 4.22%
1 Week
218.44%
decreased by 5.17%
1 Month
215.31%
decreased by 8.30%
Analysis last updated: Tuesday, July 21, 2026 at 12:02 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 3, 2011 to Jul 17, 2026Model Insight
Volatility shocks decay with a half-life of 22 trading days, meaning a shock loses half its impact after approximately 22 days.
σ
GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 5.0000 | 12.80*** |
α ARCH Response to squared shocks | 0.0374 | 15.90*** |
β GARCH Volatility persistence | 0.9320 | 231.95*** |
Persistence:
0.969
Half-life:
22 days
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