V-Lab
State Street Materials Select Sector SPDR ETF Asy. Power MEM Volatility Analysis
Volatility prediction for Monday, September 14th, 2026
1 Day
17.12%
1 Week
16.48%
1 Month
14.77%
Analysis last updated: Saturday, September 12, 2026 at 12:04 AM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Dec 22, 1998 to Sep 11, 2026Model Insight
This asset exhibits a modest leverage effect: negative returns increase next-day volatility 46% more than equivalent positive returns. The volatility power δ = 0.97 sits below 2, so large shocks influence volatility less than quadratically, a more outlier-robust response than standard GARCH.
APMEM Model
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| Param | Value | t-stat |
|---|---|---|
| ωconst | 0.0421 | 7.72*** |
| αARCH | 0.2119 | 14.57*** |
| βGARCH | 0.7728 | 50.66*** |
| γleverage | 0.1904 | 7.62*** |
| δpower | 0.9747 | 4.21*** |
0.942
Persistence12d
Half-lifeAPMEM Model
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| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0421 | 7.72*** |
α ARCH Response to squared shocks | 0.2119 | 14.57*** |
β GARCH Volatility persistence | 0.7728 | 50.66*** |
γ leverage Additional response to negative shocks | 0.1904 | 7.62*** |
δ power Transformation power | 0.9747 | 4.21*** |
Persistence:
0.942
Half-life:
12 days
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