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Russell Midcap Index GAS-GARCH Student T Volatility Analysis

Volatility prediction for Friday, September 11th, 2026

1 Day

13.91%

increased by 0.43%

1 Week

14.07%

increased by 0.59%

1 Month

14.64%

increased by 1.16%

Analysis last updated: Saturday, September 12, 2026 at 12:49 AM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of Russell Midcap Index GAS-GARCH-T

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Mar 1, 2004 to Sep 10, 2026

Model Insight

Volatility shocks decay with a half-life of 45 trading days, meaning a shock loses half its impact after approximately 45 days. Returns follow a Student-t distribution with v = 9.52 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 45-day half-lifev = 9.52 · fat tails
ParamValuet-stat
ωconst1.3613
2.27**
αARCH0.1017
7.86***
βGARCH0.9846
129.24***
νDF9.5237
1.15

0.985

Persistence

45d

Half-life
𝑓

GAS-GARCH-T Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

1.3613
2.27**
α

ARCH

Response to squared shocks

0.1017
7.86***
β

GARCH

Volatility persistence

0.9846
129.24***
ν

DF

Student-t tail thickness

9.5237
1.15

Persistence:

0.985

Half-life:

45 days