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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

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of Tadawul All Share TASI Index S0GARCH

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Oct 19, 1998 to Aug 13, 2026

Model 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

ParameterValuet-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***
γi Spline Coefficients
K=2
γ1-0.0099
-2.73***
γ20.0126
2.72***

Persistence:

0.986

Half-life:

50 days