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CBOE Volatility Index GAS-GARCH Student T Volatility Analysis

Volatility prediction for Friday, September 18th, 2026

1 Day

129.27%

increased by 23.92%

1 Week

125.68%

increased by 20.33%

1 Month

117.21%

increased by 11.86%

Analysis last updated: Friday, September 18, 2026 at 11:35 AM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of CBOE 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, 1990 to Sep 11, 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 = 5.33 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 = 5.33 · fat tails
ParamValuet-stat
ωconst45.2707
5.09***
αARCH0.1259
6.60***
βGARCH0.9050
45.96***
νDF5.3331
2.06**

0.905

Persistence

7d

Half-life
𝑓

GAS-GARCH-T Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

45.2707
5.09***
α

ARCH

Response to squared shocks

0.1259
6.60***
β

GARCH

Volatility persistence

0.9050
45.96***
ν

DF

Student-t tail thickness

5.3331
2.06**

Persistence:

0.905

Half-life:

7 days