V-Lab
Straits Times Index STI AGARCH Volatility Analysis
Volatility prediction for Friday, September 11th, 2026
1 Day
13.00%
increased by 1.42%
1 Week
13.27%
increased by 1.69%
1 Month
14.18%
increased by 2.60%
Analysis last updated: Thursday, September 10, 2026 at 10:11 AM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 1, 1990 to Sep 4, 2026Model Insight
The news-impact curve is shifted (γ = 0.33) so that negative returns raise next-day volatility more than positive returns of the same size. The gap is largest for small shocks and narrows for larger ones.
σ
AGARCH Model
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Asymmetry: negative returns raise volatility more
| Param | Value | t-stat |
|---|---|---|
| ωconst | 0.0153 | 4.29*** |
| αARCH | 0.1193 | 10.15*** |
| βGARCH | 0.8604 | 75.56*** |
| γleverage | 0.3270 | 7.65*** |
0.980
Persistence34d
Half-lifeσ
AGARCH Model
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| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0153 | 4.29*** |
α ARCH Response to squared shocks | 0.1193 | 10.15*** |
β GARCH Volatility persistence | 0.8604 | 75.56*** |
γ leverage Additional response to negative shocks | 0.3270 | 7.65*** |
Persistence:
0.980
Half-life:
34 days
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