V-Lab
S&P 500 Index Asy. MEM Volatility Analysis
Volatility prediction for Monday, September 14th, 2026
1 Day
8.89%
decreased by 0.45%
1 Week
9.34%
decreased by 0.00%
1 Month
10.72%
increased by 1.38%
Analysis last updated: Saturday, September 12, 2026 at 12:54 AM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 1, 1990 to Sep 11, 2026Model Insight
This asset exhibits a strong leverage effect: negative returns increase next-day volatility 211% more than equivalent positive returns.
μ
AMEM Model
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Leverage: Negative returns increase volatility 211% more than positive returns
| Param | Value | t-stat |
|---|---|---|
| ωconst | 0.0240 | 9.83*** |
| αARCH | 0.0893 | 5.09*** |
| βGARCH | 0.7926 | 67.22*** |
| γleverage | 0.1882 | 6.87*** |
0.976
Persistence29d
Half-lifeμ
AMEM Model
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| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0240 | 9.83*** |
α ARCH Response to squared shocks | 0.0893 | 5.09*** |
β GARCH Volatility persistence | 0.7926 | 67.22*** |
γ leverage Additional response to negative shocks | 0.1882 | 6.87*** |
Persistence:
0.976
Half-life:
29 days
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