Dow Jones South Africa Index Spline-GARCH Volatility Analysis
Volatility prediction for Friday, July 10th, 2026
1 Day
18.29%
decreased by 0.17%
1 Week
18.44%
decreased by 0.02%
1 Month
18.95%
increased by 0.49%
Analysis last updated: Friday, July 10, 2026 at 08:30 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 1, 1992 to Apr 30, 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 33 trading days.
τ
Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.9446 | 9.32*** |
α ARCH Response to squared shocks | 0.0892 | 9.49*** |
β GARCH Volatility persistence | 0.8901 | 80.21*** |
Spline Coefficients
K=1
| γ1 | 0.0004 | 0.82 |
Persistence:
0.979
Half-life:
33 days
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