Vanguard S&P 500 Index ETF EGARCH Volatility Analysis
Volatility prediction for Monday, July 20th, 2026
1 Day
15.12%
increased by 2.65%
1 Week
15.08%
increased by 2.61%
1 Month
14.96%
increased by 2.49%
Analysis last updated: Saturday, July 18, 2026 at 09:57 AM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Nov 8, 2012 to Jul 17, 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
EGARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | -0.0081 | -2.35** |
α ARCH Response to squared shocks | 0.1647 | 25.46*** |
β GARCH Volatility persistence | 0.9465 | 291.24*** |
γ leverage Additional response to negative shocks | -0.1427 | -24.98*** |
Persistence:
0.947
Half-life:
13 days
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