V-Lab
Vanguard S&P 500 Index ETF Asy. Power MEM Volatility Analysis
Volatility prediction for Monday, August 10th, 2026
1 Day
13.24%
decreased by 2.62%
1 Week
12.18%
decreased by 3.68%
1 Month
9.96%
decreased by 5.90%
Analysis last updated: Saturday, August 8, 2026 at 09:18 AM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Nov 8, 2012 to Aug 7, 2026Model Insight
This asset exhibits a modest leverage effect: negative returns increase next-day volatility 25% more than equivalent positive returns. The volatility power δ = 0.51 sits below 2, so large shocks influence volatility less than quadratically, a more outlier-robust response than standard GARCH.
μ
APMEM Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0592 | 30.87*** |
α ARCH Response to squared shocks | 0.2468 | 47.48*** |
β GARCH Volatility persistence | 0.7102 | 123.11*** |
γ leverage Additional response to negative shocks | 0.2172 | 20.12*** |
δ power Transformation power | 0.5110 | 17.67*** |
Persistence:
0.912
Half-life:
7 days
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