V-Lab
IBEX 35 Index Zero Slope Spline-GARCH Volatility Analysis
Volatility prediction for Monday, September 14th, 2026
1 Day
13.52%
increased by 0.31%
1 Week
13.84%
increased by 0.63%
1 Month
14.79%
increased by 1.58%
Analysis last updated: Friday, September 11, 2026 at 04:07 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 2, 1990 to Sep 11, 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 17 trading days.
τ
Zero Slope Spline-GARCH Model
Tap to view equation
Time-varying baseline: volatility reverts to a slowly-shifting spline trend
| Param | Value | t-stat |
|---|---|---|
| ωconst | 0.8835 | 5.37*** |
| αARCH | 0.1105 | 9.10*** |
| βGARCH | 0.8498 | 73.67*** |
Spline Coefficients
K=8
| γ1 | -0.0348 | -0.99 |
| γ2 | 0.0742 | 1.23 |
| γ3 | -0.1024 | -2.36** |
| γ4 | 0.1461 | 4.76*** |
| γ5 | -0.1533 | -6.11*** |
| γ6 | 0.0949 | 3.47*** |
| γ7 | -0.0265 | -0.97 |
| γ8 | 0.0043 | 0.24 |
0.960
Persistence17d
Half-lifeτ
Zero Slope Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.8835 | 5.37*** |
α ARCH Response to squared shocks | 0.1105 | 9.10*** |
β GARCH Volatility persistence | 0.8498 | 73.67*** |
Spline Coefficients
K=8
| γ1 | -0.0348 | -0.99 |
| γ2 | 0.0742 | 1.23 |
| γ3 | -0.1024 | -2.36** |
| γ4 | 0.1461 | 4.76*** |
| γ5 | -0.1533 | -6.11*** |
| γ6 | 0.0949 | 3.47*** |
| γ7 | -0.0265 | -0.97 |
| γ8 | 0.0043 | 0.24 |
Persistence:
0.960
Half-life:
17 days
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