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V-Lab

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

Volatility prediction for Friday, September 18th, 2026

1 Day

64.92%

decreased by 5.18%

1 Week

68.22%

decreased by 1.88%

1 Month

75.02%

increased by 4.92%

Analysis last updated: Friday, September 18, 2026 at 10:00 PM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

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

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Mar 16, 2011 to Sep 10, 2026

Model Insight

Volatility shocks decay with a half-life of 7 trading days, meaning a shock loses half its impact after approximately 7 days. Returns follow a Student-t distribution with v = 4.11 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 7-day half-lifev = 4.11 · fat tails
ParamValuet-stat
ωconst26.5917
2.46**
αARCH0.1034
4.06***
βGARCH0.9024
21.01***
νDF4.1120
1.50

0.902

Persistence

7d

Half-life
𝑓

GAS-GARCH-T Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

26.5917
2.46**
α

ARCH

Response to squared shocks

0.1034
4.06***
β

GARCH

Volatility persistence

0.9024
21.01***
ν

DF

Student-t tail thickness

4.1120
1.50

Persistence:

0.902

Half-life:

7 days