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V-Lab

CBOE Skew Index GAS-GARCH Student T Volatility Analysis

Volatility prediction for Friday, August 21st, 2026

1 Day

36.85%

decreased by 3.49%

1 Week

37.11%

decreased by 3.23%

1 Month

38.05%

decreased by 2.29%

Analysis last updated: Friday, August 21, 2026 at 11:30 AM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of CBOE Skew 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 Aug 14, 2026

Model Insight

Volatility shocks decay with a half-life of 47 trading days, meaning a shock loses half its impact after approximately 47 days. Returns follow a Student-t distribution with v = 4.39 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

8.0603
5.15***
α

ARCH

Response to squared shocks

0.1020
43.63***
β

GARCH

Volatility persistence

0.9855
365.53***
ν

DF

Student-t tail thickness

4.3938
16.21***

Persistence:

0.985

Half-life:

47 days