V-Lab
CBOE S&P 500 Left Tail Volatility Index GJR-GARCH Volatility Analysis
Volatility prediction for Friday, August 21st, 2026
1 Day
179.15%
decreased by 2.95%
1 Week
183.04%
increased by 0.94%
1 Month
196.32%
increased by 14.22%
Analysis last updated: Friday, August 21, 2026 at 11:30 AM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 3, 2006 to Aug 14, 2026Model Insight
Volatility shocks decay with a half-life of 41 trading days, meaning a shock loses half its impact after approximately 41 days.
σ
GJR-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 5.0000 | 14.88*** |
α ARCH Response to squared shocks | 0.0973 | 12.57*** |
β GARCH Volatility persistence | 0.8799 | 226.07*** |
γ leverage Additional response to negative shocks | 0.0118 | 0.71 |
Persistence:
0.983
Half-life:
41 days
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