V-Lab
Korea Stock Exchange KOSPI Index GJR-GARCH Volatility Analysis
Volatility prediction for Tuesday, August 18th, 2026
1 Day
74.99%
decreased by 3.39%
1 Week
74.78%
decreased by 3.60%
1 Month
73.96%
decreased by 4.42%
Analysis last updated: Friday, August 14, 2026 at 09:09 AM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 2, 1990 to Aug 14, 2026Model Insight
With persistence 0.996, volatility shocks have a half-life of 190 trading days (~0.8 years), close to a unit root, so long-run forecasts are highly sensitive to this estimate.
Leverage: Negative returns increase volatility 120% more than positive returns
σ
GJR-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0191 | 20.45*** |
α ARCH Response to squared shocks | 0.0598 | 23.08*** |
β GARCH Volatility persistence | 0.9007 | 520.62*** |
γ leverage Additional response to negative shocks | 0.0718 | 14.41*** |
Persistence:
0.996
Half-life:
190 days
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