Skip to main content
V-Lab

CBOE Google Volatility Index GAS-GARCH Student T Volatility Analysis

Volatility prediction for Tuesday, July 21st, 2026

1 Day

82.20%

decreased by 8.39%

1 Week

91.26%

increased by 0.67%

1 Month

110.28%

increased by 19.69%

Analysis last updated: Tuesday, July 21, 2026 at 12:02 PM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of CBOE Google Volatility Index GAS-GARCH-T

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Jan 7, 2011 to Jul 17, 2026

Model Insight

Volatility shocks decay with a half-life of 8 trading days, meaning a shock loses half its impact after approximately 8 days. Returns follow a Student-t distribution with v = 2.83 degrees of freedom, capturing fatter tails than a normal distribution.

𝑓

GAS-GARCH-T Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

68.9953
3.81***
α

ARCH

Response to squared shocks

0.1304
14.93***
β

GARCH

Volatility persistence

0.9199
41.74***
ν

DF

Student-t tail thickness

2.8333
12.42***

Persistence:

0.920

Half-life:

8 days