V-Lab
Stock Exchange of Thailand SET 50 Index Zero Slope Spline-GARCH Volatility Analysis
Volatility prediction for Friday, September 18th, 2026
1 Day
12.76%
increased by 1.14%
1 Week
13.01%
increased by 1.39%
1 Month
13.71%
increased by 2.09%
Analysis last updated: Friday, September 18, 2026 at 09:55 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Aug 16, 1995 to Sep 17, 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 15 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 | 0.6278 | 3.96*** |
| αARCH | 0.1124 | 8.71*** |
| βGARCH | 0.8434 | 48.21*** |
Spline Coefficients
K=8
| γ1 | -0.2731 | -4.46*** |
| γ2 | 0.3964 | 4.20*** |
| γ3 | -0.2068 | -2.24** |
| γ4 | 0.1056 | 0.97 |
| γ5 | -0.0342 | -0.36 |
| γ6 | 0.0659 | 1.06 |
| γ7 | -0.0841 | -1.64 |
| γ8 | 0.0365 | 0.93 |
0.956
Persistence15d
Half-lifeτ
Zero Slope Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.6278 | 3.96*** |
α ARCH Response to squared shocks | 0.1124 | 8.71*** |
β GARCH Volatility persistence | 0.8434 | 48.21*** |
Spline Coefficients
K=8
| γ1 | -0.2731 | -4.46*** |
| γ2 | 0.3964 | 4.20*** |
| γ3 | -0.2068 | -2.24** |
| γ4 | 0.1056 | 0.97 |
| γ5 | -0.0342 | -0.36 |
| γ6 | 0.0659 | 1.06 |
| γ7 | -0.0841 | -1.64 |
| γ8 | 0.0365 | 0.93 |
Persistence:
0.956
Half-life:
15 days
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