V-Lab
S&P 500 Growth Index GJR-GARCH Volatility Analysis
Volatility prediction for Friday, July 31st, 2026
1 Day
22.03%
decreased by 0.60%
1 Week
21.96%
decreased by 0.67%
1 Month
21.70%
decreased by 0.93%
Analysis last updated: Thursday, July 30, 2026 at 11:06 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Oct 29, 1992 to Jul 24, 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 | 0.0210 | 20.16*** |
α ARCH Response to squared shocks | 0.0074 | 2.36** |
β GARCH Volatility persistence | 0.9013 | 383.03*** |
γ leverage Additional response to negative shocks | 0.1545 | 28.89*** |
Persistence:
0.986
Half-life:
49 days
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