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S&P Composite 1500 Index GAS-GARCH Student T Volatility Analysis

Volatility prediction for Friday, October 23rd, 2026

1 Day

12.58%

increased by 1.29%

1 Week

12.74%

increased by 1.45%

1 Month

13.31%

increased by 2.02%

Analysis last updated: Thursday, October 22, 2026 at 11:08 PM UTC

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Date Range:

from

10/22/2024

to

10/22/2026

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of S&P Composite 1500 Index GAS-GARCH-T

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Oct 31, 1994 to Oct 16, 2026

Model Insight

Volatility shocks decay with a half-life of 58 trading days, meaning a shock loses half its impact after approximately 58 days. Returns follow a Student-t distribution with v = 7.58 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 58-day half-lifev = 7.58 · fat tails
ParamValuet-stat
ωlong-run1.3127
1.81*
αscore0.0920
9.57***
βpersistence0.9880
134.70***
νDF7.5817
1.73*

0.988

Persistence

58d

Half-life
𝑓

GAS-GARCH-T Model

Tap to view equation

ParameterValuet-statistic
ω

long-run

Long-run variance given a price move

1.3127
1.81*
α

score

Weight on the scaled score

0.0920
9.57***
β

persistence

Volatility persistence

0.9880
134.70***
ν

DF

Student-t tail thickness

7.5817
1.73*

Persistence:

0.988

Half-life:

58 days