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V-Lab
V-Lab

Travelzoo Inc APARCH Volatility Analysis

Volatility prediction for Wednesday, September 9th, 2026

1 Day

48.93%

decreased by 0.68%

1 Week

51.10%

increased by 1.49%

1 Month

58.63%

increased by 9.02%

Analysis last updated: Tuesday, September 8, 2026 at 10:40 PM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of Travelzoo Inc APARCH

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Aug 29, 2002 to Sep 4, 2026

Model 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.

σ

APARCH Model

Tap to view equation

Shock decay: Shocks decay with a 33-day half-lifeδ = 1.22 · sub-quadratic power
ParamValuet-stat
ωconst0.1910
2.08**
αARCH0.0807
4.63***
βGARCH0.9130
51.71***
γleverage-0.2335
-1.86*
δpower1.2233
4.09***

0.979

Persistence

33d

Half-life
σ

APARCH Model

Tap to view equation

ParameterValuet-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