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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

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of Vanguard S&P 500 Index ETF APMEM

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Nov 8, 2012 to Aug 7, 2026

Model 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

ParameterValuet-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