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

Volatility prediction for Friday, July 24th, 2026

1 Day

28.36%

increased by 2.36%

1 Week

30.11%

increased by 4.11%

1 Month

34.54%

increased by 8.54%

Analysis last updated: Friday, July 24, 2026 at 11:32 AM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

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graph of CBOE S&P 500 One-Year 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, 2007 to Jul 17, 2026

Model Insight

Volatility shocks decay with a half-life of 12 trading days, meaning a shock loses half its impact after approximately 12 days. Returns follow a Student-t distribution with v = 4.89 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

6.9866
8.61***
α

ARCH

Response to squared shocks

0.1696
25.56***
β

GARCH

Volatility persistence

0.9434
142.55***
ν

DF

Student-t tail thickness

4.8890
9.85***

Persistence:

0.943

Half-life:

12 days