V-Lab
CBOE S&P 500 9-Day Volatility Index GJR-GARCH Volatility Analysis
Volatility prediction for Friday, September 11th, 2026
1 Day
196.45%
increased by 2.97%
1 Week
195.80%
increased by 2.32%
1 Month
193.74%
increased by 0.26%
Analysis last updated: Friday, September 11, 2026 at 11:30 AM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 3, 2011 to Sep 4, 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 | 2.03** |
| αARCH | 0.0569 | 2.93*** |
| βGARCH | 0.9355 | 58.51*** |
| γleverage | -0.0569 | -1.54 |
0.964
Persistence19d
Half-lifeσ
GJR-GARCH Model
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| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 5.0000 | 2.03** |
α ARCH Response to squared shocks | 0.0569 | 2.93*** |
β GARCH Volatility persistence | 0.9355 | 58.51*** |
γ leverage Additional response to negative shocks | -0.0569 | -1.54 |
Persistence:
0.964
Half-life:
19 days
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