V-Lab
Straits Times Index STI Spline-GARCH Volatility Analysis
Volatility prediction for Monday, September 14th, 2026
1 Day
10.57%
decreased by 0.57%
1 Week
10.94%
decreased by 0.20%
1 Month
11.97%
increased by 0.83%
Analysis last updated: Friday, September 11, 2026 at 10:04 AM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 1, 1990 to Sep 11, 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 13 trading days.
τ
Spline-GARCH Model
Tap to view equation
Time-varying baseline: volatility reverts to a slowly-shifting spline trend
| Param | Value | t-stat |
|---|---|---|
| ωconst | 1.1461 | 4.91*** |
| αARCH | 0.1332 | 8.36*** |
| βGARCH | 0.8147 | 43.61*** |
Spline Coefficients
K=9
| γ1 | -0.0256 | -0.64 |
| γ2 | 0.1150 | 2.00** |
| γ3 | -0.2264 | -6.05*** |
| γ4 | 0.2609 | 7.40*** |
| γ5 | -0.2196 | -5.78*** |
| γ6 | 0.1430 | 3.87*** |
| γ7 | -0.0324 | -0.91 |
| γ8 | -0.0490 | -1.28 |
| γ9 | 0.0703 | 1.31 |
0.948
Persistence13d
Half-lifeτ
Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 1.1461 | 4.91*** |
α ARCH Response to squared shocks | 0.1332 | 8.36*** |
β GARCH Volatility persistence | 0.8147 | 43.61*** |
Spline Coefficients
K=9
| γ1 | -0.0256 | -0.64 |
| γ2 | 0.1150 | 2.00** |
| γ3 | -0.2264 | -6.05*** |
| γ4 | 0.2609 | 7.40*** |
| γ5 | -0.2196 | -5.78*** |
| γ6 | 0.1430 | 3.87*** |
| γ7 | -0.0324 | -0.91 |
| γ8 | -0.0490 | -1.28 |
| γ9 | 0.0703 | 1.31 |
Persistence:
0.948
Half-life:
13 days
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