V-Lab
Korea Stock Exchange KOSPI Index GAS-GARCH Student T Volatility Analysis
Volatility prediction for Monday, September 28th, 2026
1 Day
38.12%
1 Week
38.04%
1 Month
37.73%
Analysis last updated: Wednesday, September 23, 2026 at 09:12 AM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 2, 1990 to Sep 23, 2026Model Insight
With persistence 0.995, volatility shocks have a half-life of 150 trading days (~0.6 years), close to a unit root, so long-run forecasts are highly sensitive to this estimate. Returns follow a Student-t distribution with v = 7.15 degrees of freedom, capturing fatter tails than a normal distribution.
GAS-GARCH-T Model
Tap to view equation
| Param | Value | t-stat |
|---|---|---|
| ωconst | 3.1607 | 1.41 |
| αARCH | 0.0757 | 12.87*** |
| βGARCH | 0.9954 | 325.18*** |
| νDF | 7.1518 | 2.38** |
0.995
Persistence150d
Half-lifeGAS-GARCH-T Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 3.1607 | 1.41 |
α ARCH Response to squared shocks | 0.0757 | 12.87*** |
β GARCH Volatility persistence | 0.9954 | 325.18*** |
ν DF Student-t tail thickness | 7.1518 | 2.38** |
Persistence:
0.995
Half-life:
150 days
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