CBOE S&P 500 9-Day Volatility Index GJR-GARCH Volatility Analysis
Volatility prediction for Friday, October 23rd, 2026
1 Day
219.78%
increased by 9.17%
1 Week
217.68%
increased by 7.07%
1 Month
210.87%
increased by 0.26%
Analysis last updated: Friday, October 23, 2026 at 11:33 AM UTC
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News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 3, 2011 to Oct 16, 2026Model Insight
Volatility shocks decay with a half-life of 19 trading days, meaning a shock loses half its impact after approximately 19 days.
σ
GJR-GARCH Model
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Shock decay: Shocks decay with a 19-day half-life
| Param | Value | t-stat |
|---|---|---|
| ωconst | 5.0000 | 2.05** |
| αARCH | 0.0567 | 2.96*** |
| βGARCH | 0.9357 | 58.59*** |
| γleverage | -0.0567 | -1.56 |
0.964
Persistence19d
Half-lifeσ
GJR-GARCH Model
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| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 5.0000 | 2.05** |
α ARCH Response to squared shocks | 0.0567 | 2.96*** |
β GARCH Volatility persistence | 0.9357 | 58.59*** |
γ leverage Additional response to negative shocks | -0.0567 | -1.56 |
Persistence:
0.964
Half-life:
19 days
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