Skip to main content
V-Lab

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

Volatility prediction for Monday, August 17th, 2026

1 Day

17.38%

decreased by 0.71%

1 Week

17.51%

decreased by 0.58%

1 Month

17.98%

decreased by 0.11%

Analysis last updated: Saturday, August 15, 2026 at 05:47 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 Aug 14, 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 = 6.36 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

1.6487
11.81***
α

ARCH

Response to squared shocks

0.0830
38.61***
β

GARCH

Volatility persistence

0.9784
515.49***
ν

DF

Student-t tail thickness

6.3605
8.12***

Persistence:

0.978

Half-life:

32 days