V-Lab
CBOE Skew Index Zero Slope Spline-GARCH Volatility Analysis
Volatility prediction for Friday, July 24th, 2026
1 Day
45.74%
increased by 2.86%
1 Week
48.19%
increased by 5.31%
1 Month
51.20%
increased by 8.32%
Analysis last updated: Friday, July 24, 2026 at 11:31 AM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 2, 1990 to Jul 17, 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 3 trading days.
τ
Zero Slope Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 2.8539 | 4.22*** |
α ARCH Response to squared shocks | 0.2670 | 11.07*** |
β GARCH Volatility persistence | 0.5278 | 15.00*** |
Spline Coefficients
K=10
| γ1 | 0.0942 | 2.06** |
| γ2 | -0.0490 | -0.80 |
| γ3 | -0.0869 | -2.00** |
| γ4 | 0.1323 | 2.92*** |
| γ5 | -0.2067 | -5.28*** |
| γ6 | 0.2116 | 5.66*** |
| γ7 | -0.1248 | -3.68*** |
| γ8 | -0.0286 | -0.87 |
| γ9 | 0.1345 | 4.14*** |
| γ10 | -0.1089 | -4.64*** |
Persistence:
0.795
Half-life:
3 days
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