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Russell 1000 Growth Index GAS-GARCH Student T Volatility Analysis

Volatility prediction for Monday, July 27th, 2026

1 Day

24.57%

increased by 0.37%

1 Week

24.59%

increased by 0.39%

1 Month

24.66%

increased by 0.46%

Analysis last updated: Saturday, July 25, 2026 at 12:05 AM UTC

Date Range:

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to

6M ·

1Y ·

2Y ·

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10Y ·

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graph of Russell 1000 Growth Index GAS-GARCH-T

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

May 12, 2000 to Jul 24, 2026

Model Insight

With persistence 0.995, volatility shocks have a half-life of 126 trading days (~0.5 years), close to a unit root, so long-run forecasts are highly sensitive to this estimate. Returns follow a Student-t distribution with v = 8.36 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

2.7328
4.37***
α

ARCH

Response to squared shocks

0.0952
39.45***
β

GARCH

Volatility persistence

0.9945
777.59***
ν

DF

Student-t tail thickness

8.3621
6.60***

Persistence:

0.995

Half-life:

126 days