V-Lab
Tadawul All Share TASI Index Zero Slope Spline-GARCH Volatility Analysis
Volatility prediction for Saturday, August 15th, 2026
1 Day
10.69%
decreased by 0.68%
1 Week
11.20%
decreased by 0.17%
1 Month
12.91%
increased by 1.54%
Analysis last updated: Friday, August 14, 2026 at 05:41 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Oct 19, 1998 to Aug 13, 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 50 trading days.
τ
Zero Slope Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.8700 | 3.37*** |
α ARCH Response to squared shocks | 0.1720 | 11.43*** |
β GARCH Volatility persistence | 0.8141 | 61.94*** |
Spline Coefficients
K=2
| γ1 | -0.0099 | -2.73*** |
| γ2 | 0.0126 | 2.72*** |
Persistence:
0.986
Half-life:
50 days
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