V-Lab
CBOE Volatility Index Zero Slope Spline-GARCH Volatility Analysis
Volatility prediction for Friday, August 21st, 2026
1 Day
113.20%
increased by 4.28%
1 Week
117.83%
increased by 8.91%
1 Month
125.34%
increased by 16.42%
Analysis last updated: Friday, August 21, 2026 at 11:34 AM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 2, 1990 to Aug 14, 2026Model Insight
This model fits a time-varying baseline (a spline), so volatility mean-reverts toward a slowly-shifting long-run level rather than a constant. Short-run deviations decay with a half-life of 4 trading days.
τ
Zero Slope Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.9784 | 10.36*** |
α ARCH Response to squared shocks | 0.1366 | 7.50*** |
β GARCH Volatility persistence | 0.7159 | 20.17*** |
Spline Coefficients
K=2
| γ1 | 0.0026 | 3.10*** |
| γ2 | -0.0038 | -3.70*** |
Persistence:
0.852
Half-life:
4 days
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