S&P Total Market Index Asy. MEM Volatility Analysis
Volatility prediction for Thursday, October 8th, 2026
1 Day
9.58%
increased by 0.08%
1 Week
10.38%
increased by 0.88%
1 Month
12.54%
increased by 3.04%
Analysis last updated: Wednesday, October 7, 2026 at 11:04 PM UTC
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News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Oct 20, 2011 to Oct 2, 2026Model Insight
This asset exhibits a strong leverage effect: negative returns increase next-day volatility 130% more than equivalent positive returns.
μ
AMEM Model
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Leverage: Negative returns increase volatility 130% more than positive returns
| Param | Value | t-stat |
|---|---|---|
| ωconst | 0.0472 | 7.91*** |
| αARCH | 0.1849 | 4.12*** |
| βGARCH | 0.6558 | 24.16*** |
| γleverage | 0.2400 | 3.80*** |
0.961
Persistence17d
Half-lifeμ
AMEM Model
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| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0472 | 7.91*** |
α ARCH Response to squared shocks | 0.1849 | 4.12*** |
β GARCH Volatility persistence | 0.6558 | 24.16*** |
γ leverage Additional response to negative shocks | 0.2400 | 3.80*** |
Persistence:
0.961
Half-life:
17 days
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