V-Lab
Vanguard S&P 500 Index ETF GJR-GARCH Volatility Analysis
Volatility prediction for Monday, July 27th, 2026
1 Day
14.10%
decreased by 0.78%
1 Week
14.15%
decreased by 0.73%
1 Month
14.30%
decreased by 0.58%
Analysis last updated: Saturday, July 25, 2026 at 09:13 AM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Nov 8, 2012 to Jul 24, 2026Model Insight
Volatility shocks decay with a half-life of 13 trading days, meaning a shock loses half its impact after approximately 13 days.
σ
GJR-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0430 | 16.19*** |
α ARCH Response to squared shocks | 0.0000 | 0.00 |
β GARCH Volatility persistence | 0.8487 | 186.48*** |
γ leverage Additional response to negative shocks | 0.2017 | 16.68*** |
Persistence:
0.950
Half-life:
13 days
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