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CBOE S&P 500 Spot Volatility Index GAS-GARCH Student T Volatility Analysis

Volatility prediction for Monday, October 26th, 2026

1 Day

202.80%

decreased by 13.11%

1 Week

205.74%

decreased by 10.17%

1 Month

214.05%

decreased by 1.86%

Analysis last updated: Monday, October 26, 2026 at 11:32 AM UTC

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Date Range:

from

10/23/2024

to

10/23/2026

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of CBOE S&P 500 Spot Volatility Index GAS-GARCH-T

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Jan 3, 2006 to Oct 23, 2026

Model Insight

Volatility shocks decay with a half-life of 14 trading days, meaning a shock loses half its impact after approximately 14 days. Returns follow a Student-t distribution with v = 5.67 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 14-day half-lifev = 5.67 · fat tails
ParamValuet-stat
ωlong-run215.8233
2.52**
αscore0.1180
5.20***
βpersistence0.9500
45.91***
νDF5.6731
1.59

0.950

Persistence

14d

Half-life
𝑓

GAS-GARCH-T Model

Tap to view equation

ParameterValuet-statistic
ω

long-run

Long-run variance given a price move

215.8233
2.52**
α

score

Weight on the scaled score

0.1180
5.20***
β

persistence

Volatility persistence

0.9500
45.91***
ν

DF

Student-t tail thickness

5.6731
1.59

Persistence:

0.950

Half-life:

14 days