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
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Apr 25, 2003 to Sep 11, 2026Model Insight
This asset exhibits a strong leverage effect: negative returns increase next-day volatility 155% more than equivalent positive returns.
μ
AMEM Model
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Leverage: Negative returns increase volatility 155% more than positive returns
| Param | Value | t-stat |
|---|---|---|
| ωconst | 0.0256 | 7.11*** |
| αARCH | 0.1130 | 5.98*** |
| βGARCH | 0.7792 | 60.23*** |
| γleverage | 0.1753 | 5.40*** |
0.980
Persistence34d
Half-lifeμ
AMEM Model
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| Parameter | Value | t-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
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