V-Lab
Blom Stock Index GJR-GARCH Volatility Analysis
High-persistence model: shocks decay very slowly, so the theoretical long-run value may not be practically meaningful
Volatility prediction for Friday, September 18th, 2026
1 Day
14.16%
1 Week
14.83%
1 Month
17.27%
Analysis last updated: Friday, September 18, 2026 at 10:07 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 19, 1996 to Sep 10, 2026Model Insight
With persistence 1.000, volatility shocks have a half-life of 1386294 trading days (~5501.2 years), close to a unit root, so long-run forecasts are highly sensitive to this estimate.
GJR-GARCH Model
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| Param | Value | t-stat |
|---|---|---|
| ωconst | 0.0387 | 6.10*** |
| αARCH | 0.2589 | 4.90*** |
| βGARCH | 0.7629 | 32.55*** |
| γleverage | -0.0435 | -0.54 |
1.000
Persistence1386294d
Half-lifeGJR-GARCH Model
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| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0387 | 6.10*** |
α ARCH Response to squared shocks | 0.2589 | 4.90*** |
β GARCH Volatility persistence | 0.7629 | 32.55*** |
γ leverage Additional response to negative shocks | -0.0435 | -0.54 |
Persistence:
1.000
Half-life:
1386294 days
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