Skip to main content
V-Lab
V-Lab

Russell 1000 Growth Index GAS-GARCH Student T Volatility Analysis

Volatility prediction for Wednesday, October 21st, 2026

1 Day

17.69%

decreased by 1.15%

1 Week

17.80%

decreased by 1.04%

1 Month

18.23%

decreased by 0.61%

Analysis last updated: Wednesday, October 21, 2026 at 09:03 AM UTC

Press Delete or Backspace to remove this series.
Date Range:

from

10/20/2024

to

10/20/2026

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

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 Oct 16, 2026

Model Insight

With persistence 0.994, volatility shocks have a half-life of 122 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 = 8.38 degrees of freedom, capturing fatter tails than a normal distribution.

𝑓

GAS-GARCH-T Model

Tap to view equation

High persistence: persistence 0.994, shock half-life ~122 daysv = 8.38 · fat tails
ParamValuet-stat
ωlong-run2.6520
1.09
αscore0.0948
9.72***
βpersistence0.9943
187.36***
νDF8.3788
1.63

0.994

Persistence

122d

Half-life
𝑓

GAS-GARCH-T Model

Tap to view equation

ParameterValuet-statistic
ω

long-run

Long-run variance given a price move

2.6520
1.09
α

score

Weight on the scaled score

0.0948
9.72***
β

persistence

Volatility persistence

0.9943
187.36***
ν

DF

Student-t tail thickness

8.3788
1.63

Persistence:

0.994

Half-life:

122 days