V-Lab
S&P 1000 Index GJR-GARCH Volatility Analysis
Volatility prediction for Tuesday, September 22nd, 2026
1 Day
13.87%
decreased by 0.51%
1 Week
14.14%
decreased by 0.24%
1 Month
15.06%
increased by 0.68%
Analysis last updated: Monday, September 21, 2026 at 11:01 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Dec 29, 1994 to Sep 18, 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 | 0.0284 | 5.93*** |
| αARCH | 0.0137 | 1.83* |
| βGARCH | 0.8934 | 117.87*** |
| γleverage | 0.1510 | 7.49*** |
0.983
Persistence40d
Half-lifeσ
GJR-GARCH Model
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| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0284 | 5.93*** |
α ARCH Response to squared shocks | 0.0137 | 1.83* |
β GARCH Volatility persistence | 0.8934 | 117.87*** |
γ leverage Additional response to negative shocks | 0.1510 | 7.49*** |
Persistence:
0.983
Half-life:
40 days
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