V-Lab
Korea Stock Exchange KOSPI Index GJR-GARCH Volatility Analysis
Volatility prediction for Wednesday, September 16th, 2026
1 Day
43.13%
decreased by 1.99%
1 Week
43.07%
decreased by 2.05%
1 Month
42.85%
decreased by 2.27%
Analysis last updated: Tuesday, September 15, 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 Sep 11, 2026Model Insight
With persistence 0.996, volatility shocks have a half-life of 172 trading days (~0.7 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
High persistence: persistence 0.996, shock half-life ~172 daysLeverage: Negative returns increase volatility 120% more than positive returns
| Param | Value | t-stat |
|---|---|---|
| ωconst | 0.0197 | 5.24*** |
| αARCH | 0.0605 | 5.79*** |
| βGARCH | 0.8991 | 129.11*** |
| γleverage | 0.0727 | 3.61*** |
0.996
Persistence172d
Half-lifeσ
GJR-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0197 | 5.24*** |
α ARCH Response to squared shocks | 0.0605 | 5.79*** |
β GARCH Volatility persistence | 0.8991 | 129.11*** |
γ leverage Additional response to negative shocks | 0.0727 | 3.61*** |
Persistence:
0.996
Half-life:
172 days
Other Korea Stock Exchange KOSPI Index Analyses
Other GJR-GARCH Analyses on Equity Indices