Skip to main content
V-Lab
V-Lab

Nikkei Stock Average Volatility Index GAS-GARCH Student T Volatility Analysis

Volatility prediction for Monday, September 28th, 2026

1 Day

116.80%

decreased by 11.77%

1 Week

115.02%

decreased by 13.55%

1 Month

110.05%

decreased by 18.52%

Analysis last updated: Friday, October 2, 2026 at 09:43 PM UTC

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

from

09/25/2024

to

09/25/2026

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of Nikkei Stock Average Volatility Index GAS-GARCH-T

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Jan 3, 1990 to Sep 25, 2026

Model Insight

Volatility shocks decay with a half-life of 11 trading days, meaning a shock loses half its impact after approximately 11 days. Returns follow a Student-t distribution with v = 4.59 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 11-day half-lifev = 4.59 · fat tails
ParamValuet-stat
ωconst39.9218
3.14***
αARCH0.1186
7.35***
βGARCH0.9390
50.33***
νDF4.5913
2.61***

0.939

Persistence

11d

Half-life
𝑓

GAS-GARCH-T Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

39.9218
3.14***
α

ARCH

Response to squared shocks

0.1186
7.35***
β

GARCH

Volatility persistence

0.9390
50.33***
ν

DF

Student-t tail thickness

4.5913
2.61***

Persistence:

0.939

Half-life:

11 days