V-Lab
SEI Select Small CAP ETF APARCH Volatility Analysis
Volatility prediction for Wednesday, September 16th, 2026
1 Day
22.05%
1 Week
22.11%
1 Month
22.29%
Analysis last updated: Wednesday, September 16, 2026 at 02:37 AM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Oct 10, 2024 to Sep 11, 2026Model Insight
Volatility shocks decay with a half-life of 14 trading days, meaning a shock loses half its impact after approximately 14 days. The volatility power δ = 1.23 sits below 2, so large shocks influence volatility less than quadratically, a more outlier-robust response than standard GARCH.
APARCH Model
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| Param | Value | t-stat |
|---|---|---|
| ωconst | 0.0767 | 0.77 |
| αARCH | 0.0522 | 0.27 |
| βGARCH | 0.9004 | 10.79*** |
| γleverage | 1.0000 | 0.17 |
| δpower | 1.2349 | 1.36 |
0.951
Persistence14d
Half-lifeAPARCH Model
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| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0767 | 0.77 |
α ARCH Response to squared shocks | 0.0522 | 0.27 |
β GARCH Volatility persistence | 0.9004 | 10.79*** |
γ leverage Additional response to negative shocks | 1.0000 | 0.17 |
δ power Transformation power | 1.2349 | 1.36 |
Persistence:
0.951
Half-life:
14 days
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