V-Lab
CBOE S&P 500 9-Day Volatility Index GJR-GARCH Volatility Analysis
Volatility prediction for Friday, October 2nd, 2026
1 Day
177.26%
decreased by 2.29%
1 Week
177.96%
decreased by 1.59%
1 Month
180.16%
increased by 0.61%
Analysis last updated: Friday, October 2, 2026 at 11:31 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 Sep 25, 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 | 2.04** |
| αARCH | 0.0568 | 2.95*** |
| βGARCH | 0.9356 | 58.55*** |
| γleverage | -0.0568 | -1.55 |
0.964
Persistence19d
Half-lifeσ
GJR-GARCH Model
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| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 5.0000 | 2.04** |
α ARCH Response to squared shocks | 0.0568 | 2.95*** |
β GARCH Volatility persistence | 0.9356 | 58.55*** |
γ leverage Additional response to negative shocks | -0.0568 | -1.55 |
Persistence:
0.964
Half-life:
19 days
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