V-Lab
Straits Times Index STI Zero Slope Spline-GARCH Volatility Analysis
Volatility prediction for Monday, September 14th, 2026
1 Day
10.04%
decreased by 0.60%
1 Week
10.31%
decreased by 0.33%
1 Month
11.05%
increased by 0.41%
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
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 | 1.2093 | 5.10*** |
| αARCH | 0.1332 | 8.38*** |
| βGARCH | 0.8152 | 43.88*** |
Spline Coefficients
K=9
| γ1 | -0.0087 | -0.22 |
| γ2 | 0.0875 | 1.52 |
| γ3 | -0.2063 | -5.47*** |
| γ4 | 0.2416 | 6.81*** |
| γ5 | -0.2015 | -5.29*** |
| γ6 | 0.1305 | 3.53*** |
| γ7 | -0.0296 | -0.85 |
| γ8 | -0.0394 | -1.15 |
| γ9 | 0.0367 | 1.39 |
0.948
Persistence13d
Half-lifeτ
Zero Slope Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 1.2093 | 5.10*** |
α ARCH Response to squared shocks | 0.1332 | 8.38*** |
β GARCH Volatility persistence | 0.8152 | 43.88*** |
Spline Coefficients
K=9
| γ1 | -0.0087 | -0.22 |
| γ2 | 0.0875 | 1.52 |
| γ3 | -0.2063 | -5.47*** |
| γ4 | 0.2416 | 6.81*** |
| γ5 | -0.2015 | -5.29*** |
| γ6 | 0.1305 | 3.53*** |
| γ7 | -0.0296 | -0.85 |
| γ8 | -0.0394 | -1.15 |
| γ9 | 0.0367 | 1.39 |
Persistence:
0.948
Half-life:
13 days
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