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V-Lab

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

Volatility prediction for Monday, August 3rd, 2026

1 Day

108.83%

decreased by 14.59%

1 Week

107.77%

decreased by 15.65%

1 Month

104.88%

decreased by 18.54%

Analysis last updated: Friday, August 7, 2026 at 08:40 PM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

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10Y ·

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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 Jul 31, 2026

Model Insight

Volatility shocks decay with a half-life of 10 trading days, meaning a shock loses half its impact after approximately 10 days. Returns follow a Student-t distribution with v = 4.61 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

39.4817
13.10***
α

ARCH

Response to squared shocks

0.1215
29.13***
β

GARCH

Volatility persistence

0.9350
195.61***
ν

DF

Student-t tail thickness

4.6148
10.41***

Persistence:

0.935

Half-life:

10 days