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Tokyo Stock Exchange Tokyo Stock Price Index TOPIX GAS-GARCH Student T Volatility Analysis

Volatility prediction for Monday, September 7th, 2026

1 Day

16.15%

decreased by 0.99%

1 Week

16.35%

decreased by 0.79%

1 Month

17.02%

decreased by 0.12%

Analysis last updated: Saturday, September 5, 2026 at 05:57 PM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of Tokyo Stock Exchange Tokyo Stock Price Index TOPIX GAS-GARCH-T

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Jan 2, 1990 to Sep 4, 2026

Model Insight

Volatility shocks decay with a half-life of 32 trading days, meaning a shock loses half its impact after approximately 32 days. Returns follow a Student-t distribution with v = 6.32 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 32-day half-lifev = 6.32 · fat tails
ParamValuet-stat
ωconst1.6472
2.92***
αARCH0.0826
9.61***
βGARCH0.9784
127.93***
νDF6.3220
2.03**

0.978

Persistence

32d

Half-life
𝑓

GAS-GARCH-T Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

1.6472
2.92***
α

ARCH

Response to squared shocks

0.0826
9.61***
β

GARCH

Volatility persistence

0.9784
127.93***
ν

DF

Student-t tail thickness

6.3220
2.03**

Persistence:

0.978

Half-life:

32 days