V-Lab
Tadawul All Share TASI Index Zero Slope Spline-GARCH Volatility Analysis
Volatility prediction for Saturday, September 26th, 2026
1 Day
9.90%
decreased by 0.65%
1 Week
10.47%
decreased by 0.08%
1 Month
12.34%
increased by 1.79%
Analysis last updated: Thursday, September 24, 2026 at 05:43 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Oct 19, 1998 to Sep 23, 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 49 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 | 0.8661 | 3.43*** |
| αARCH | 0.1713 | 11.42*** |
| βGARCH | 0.8146 | 62.15*** |
Spline Coefficients
K=2
| γ1 | -0.0098 | -2.72*** |
| γ2 | 0.0124 | 2.71*** |
0.986
Persistence49d
Half-lifeτ
Zero Slope Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.8661 | 3.43*** |
α ARCH Response to squared shocks | 0.1713 | 11.42*** |
β GARCH Volatility persistence | 0.8146 | 62.15*** |
Spline Coefficients
K=2
| γ1 | -0.0098 | -2.72*** |
| γ2 | 0.0124 | 2.71*** |
Persistence:
0.986
Half-life:
49 days
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