V-Lab
Travelzoo Inc APARCH Volatility Analysis
Volatility prediction for Wednesday, September 9th, 2026
1 Day
48.93%
1 Week
51.10%
1 Month
58.63%
Analysis last updated: Tuesday, September 8, 2026 at 10:40 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Aug 29, 2002 to Sep 4, 2026Model Insight
Volatility shocks decay with a half-life of 33 trading days, meaning a shock loses half its impact after approximately 33 days. The volatility power δ = 1.22 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 | 0.1910 | 2.08** |
| αARCH | 0.0807 | 4.63*** |
| βGARCH | 0.9130 | 51.71*** |
| γleverage | -0.2335 | -1.86* |
| δpower | 1.2233 | 4.09*** |
0.979
Persistence33d
Half-lifeAPARCH Model
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| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.1910 | 2.08** |
α ARCH Response to squared shocks | 0.0807 | 4.63*** |
β GARCH Volatility persistence | 0.9130 | 51.71*** |
γ leverage Additional response to negative shocks | -0.2335 | -1.86* |
δ power Transformation power | 1.2233 | 4.09*** |
Persistence:
0.979
Half-life:
33 days
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