Skip to main content
V-Lab
V-Lab

Nikkei 225 GAS-GARCH Student T Volatility Analysis

Volatility prediction for Wednesday, September 16th, 2026

1 Day

21.65%

decreased by 1.35%

1 Week

21.73%

decreased by 1.27%

1 Month

22.01%

decreased by 0.99%

Analysis last updated: Tuesday, September 15, 2026 at 09:03 AM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of Nikkei 225 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 11, 2026

Model Insight

Volatility shocks decay with a half-life of 41 trading days, meaning a shock loses half its impact after approximately 41 days. Returns follow a Student-t distribution with v = 7.60 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 41-day half-lifev = 7.60 · fat tails
ParamValuet-stat
ωconst2.2678
2.75***
αARCH0.0830
9.96***
βGARCH0.9831
141.04***
νDF7.6043
1.72*

0.983

Persistence

41d

Half-life
𝑓

GAS-GARCH-T Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

2.2678
2.75***
α

ARCH

Response to squared shocks

0.0830
9.96***
β

GARCH

Volatility persistence

0.9831
141.04***
ν

DF

Student-t tail thickness

7.6043
1.72*

Persistence:

0.983

Half-life:

41 days