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CBOE EFA ETF Volatility Index GAS-GARCH Student T Volatility Analysis

Volatility prediction for Thursday, September 10th, 2026

1 Day

135.00%

increased by 13.76%

1 Week

137.50%

increased by 16.26%

1 Month

144.26%

increased by 23.02%

Analysis last updated: Thursday, September 10, 2026 at 11:35 AM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of CBOE EFA ETF Volatility Index GAS-GARCH-T

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Jan 2, 2008 to Sep 4, 2026

Model Insight

Volatility shocks decay with a half-life of 12 trading days, meaning a shock loses half its impact after approximately 12 days. Returns follow a Student-t distribution with v = 3.82 degrees of freedom, capturing fatter tails than a normal distribution.

𝑓

GAS-GARCH-T Model

Tap to view equation

Shock decay: Shocks decay with a 12-day half-lifev = 3.82 · fat tails
ParamValuet-stat
ωconst97.5313
2.15**
αARCH0.1265
6.94***
βGARCH0.9432
38.90***
νDF3.8156
3.24***

0.943

Persistence

12d

Half-life
𝑓

GAS-GARCH-T Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

97.5313
2.15**
α

ARCH

Response to squared shocks

0.1265
6.94***
β

GARCH

Volatility persistence

0.9432
38.90***
ν

DF

Student-t tail thickness

3.8156
3.24***

Persistence:

0.943

Half-life:

12 days