V-Lab
Wal-Mart Stores Inc APARCH Volatility Analysis
Volatility prediction for Friday, September 11th, 2026
1 Day
25.08%
1 Week
25.25%
1 Month
25.88%
Analysis last updated: Thursday, September 10, 2026 at 09:47 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 2, 1990 to Sep 4, 2026Model Insight
This asset exhibits a notable leverage effect: negative returns increase next-day volatility 75% more than equivalent positive returns. The volatility power δ = 0.88 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 | 0.0253 | 4.15*** |
| αARCH | 0.0664 | 6.04*** |
| βGARCH | 0.9336 | 79.52*** |
| γleverage | 0.3080 | 3.13*** |
| δpower | 0.8782 | 6.34*** |
0.986
Persistence49d
Half-lifeAPARCH Model
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| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0253 | 4.15*** |
α ARCH Response to squared shocks | 0.0664 | 6.04*** |
β GARCH Volatility persistence | 0.9336 | 79.52*** |
γ leverage Additional response to negative shocks | 0.3080 | 3.13*** |
δ power Transformation power | 0.8782 | 6.34*** |
Persistence:
0.986
Half-life:
49 days
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