V-Lab
CBOE VIX Indicative Bid Index Zero Slope Spline-GARCH Volatility Analysis
Volatility prediction for Friday, August 21st, 2026
1 Day
121.63%
increased by 4.18%
1 Week
127.22%
increased by 9.77%
1 Month
134.62%
increased by 17.17%
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
Sep 18, 2009 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 3 trading days.
τ
Zero Slope Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.7389 | 5.54*** |
α ARCH Response to squared shocks | 0.1434 | 5.43*** |
β GARCH Volatility persistence | 0.6667 | 9.56*** |
Spline Coefficients
K=8
| γ1 | -0.1611 | -1.05 |
| γ2 | 0.1854 | 0.81 |
| γ3 | -0.0014 | -0.01 |
| γ4 | -0.0639 | -0.40 |
| γ5 | 0.0886 | 0.65 |
| γ6 | -0.2108 | -1.39 |
| γ7 | 0.4117 | 2.91*** |
| γ8 | -0.3636 | -4.36*** |
Persistence:
0.810
Half-life:
3 days
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