Skip to main content
V-Lab
V-Lab

S&P 500 Equal Weight Index (EWI) Asy. MEM Volatility Analysis

Volatility prediction for Monday, September 14th, 2026

1 Day

10.28%

decreased by 0.87%

1 Week

10.68%

decreased by 0.47%

1 Month

11.99%

increased by 0.84%

Analysis last updated: Saturday, September 12, 2026 at 12:53 AM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of S&P 500 Equal Weight Index (EWI) AMEM

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Apr 25, 2003 to Sep 11, 2026

Model Insight

This asset exhibits a strong leverage effect: negative returns increase next-day volatility 155% more than equivalent positive returns.

μ

AMEM Model

Tap to view equation

Leverage: Negative returns increase volatility 155% more than positive returns
ParamValuet-stat
ωconst0.0256
7.11***
αARCH0.1130
5.98***
βGARCH0.7792
60.23***
γleverage0.1753
5.40***

0.980

Persistence

34d

Half-life
μ

AMEM Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

0.0256
7.11***
α

ARCH

Response to squared shocks

0.1130
5.98***
β

GARCH

Volatility persistence

0.7792
60.23***
γ

leverage

Additional response to negative shocks

0.1753
5.40***

Persistence:

0.980

Half-life:

34 days