V-Lab
S&P 500 Index GJR-GARCH Volatility Analysis
Volatility prediction for Monday, August 3rd, 2026
1 Day
14.42%
decreased by 0.58%
1 Week
14.51%
decreased by 0.49%
1 Month
14.86%
decreased by 0.14%
Analysis last updated: Saturday, August 1, 2026 at 03:07 AM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 1, 1990 to Jul 31, 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
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0216 | 20.64*** |
α ARCH Response to squared shocks | 0.0036 | 1.48 |
β GARCH Volatility persistence | 0.8973 | 417.18*** |
γ leverage Additional response to negative shocks | 0.1598 | 29.62*** |
Persistence:
0.981
Half-life:
36 days
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