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S&P MidCap 400 Index GAS-GARCH Student T Volatility Analysis

Volatility prediction for Thursday, November 5th, 2026

1 Day

13.61%

decreased by 0.09%

1 Week

13.77%

increased by 0.07%

1 Month

14.31%

increased by 0.61%

Analysis last updated: Thursday, November 5, 2026 at 12:17 AM UTC

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Date Range:

from

11/04/2024

to

11/04/2026

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of S&P MidCap 400 Index GAS-GARCH-T

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Jan 1, 1990 to Oct 30, 2026

Model Insight

Volatility shocks decay with a half-life of 51 trading days, meaning a shock loses half its impact after approximately 51 days. Returns follow a Student-t distribution with v = 11.06 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 51-day half-lifev = 11.06 · fat tails
ParamValuet-stat
ωlong-run1.3577
2.83***
αscore0.0884
9.29***
βpersistence0.9866
179.31***
νDF11.0556
1.11

0.987

Persistence

51d

Half-life
𝑓

GAS-GARCH-T Model

Tap to view equation

ParameterValuet-statistic
ω

long-run

Long-run variance given a price move

1.3577
2.83***
α

score

Weight on the scaled score

0.0884
9.29***
β

persistence

Volatility persistence

0.9866
179.31***
ν

DF

Student-t tail thickness

11.0556
1.11

Persistence:

0.987

Half-life:

51 days