V-Lab
S&P MidCap 400 Index GJR-GARCH Volatility Analysis
Volatility prediction for Tuesday, September 8th, 2026
1 Day
13.88%
decreased by 0.56%
1 Week
14.09%
decreased by 0.35%
1 Month
14.79%
increased by 0.35%
Analysis last updated: Friday, September 4, 2026 at 11:29 PM 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
This asset exhibits a strong leverage effect: volatility responds almost entirely to negative shocks. The ARCH response to positive shocks is negligible.
σ
GJR-GARCH Model
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Leverage: volatility responds almost entirely to negative shocks
| Param | Value | t-stat |
|---|---|---|
| ωconst | 0.0264 | 5.98*** |
| αARCH | 0.0204 | 2.77*** |
| βGARCH | 0.8915 | 120.52*** |
| γleverage | 0.1375 | 6.93*** |
0.981
Persistence36d
Half-lifeσ
GJR-GARCH Model
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| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0264 | 5.98*** |
α ARCH Response to squared shocks | 0.0204 | 2.77*** |
β GARCH Volatility persistence | 0.8915 | 120.52*** |
γ leverage Additional response to negative shocks | 0.1375 | 6.93*** |
Persistence:
0.981
Half-life:
36 days
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