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V-Lab

Tokyo Stock Exchange Tokyo Stock Price Index TOPIX Zero Slope Spline-GARCH Volatility Analysis

Volatility prediction for Thursday, October 1st, 2026

1 Day

17.89%

increased by 1.69%

1 Week

18.07%

increased by 1.87%

1 Month

18.66%

increased by 2.46%

Analysis last updated: Thursday, October 1, 2026 at 05:59 PM UTC

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Date Range:

from

09/30/2024

to

09/30/2026

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of Tokyo Stock Exchange Tokyo Stock Price Index TOPIX S0GARCH

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Jan 2, 1990 to Sep 25, 2026

Model Insight

This model fits a time-varying baseline (a spline), so volatility mean-reverts toward a slowly-shifting long-run level rather than a constant. Short-run deviations decay with a half-life of 21 trading days.

τ

Zero Slope Spline-GARCH Model

Tap to view equation

Time-varying baseline: volatility reverts to a slowly-shifting spline trend
ParamValuet-stat
ωconst1.0441
11.40***
αARCH0.1213
10.33***
βGARCH0.8455
69.23***
∑γi Spline Coefficients
K=1
γ10.0000
0.38

0.967

Persistence

21d

Half-life
τ

Zero Slope Spline-GARCH Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

1.0441
11.40***
α

ARCH

Response to squared shocks

0.1213
10.33***
β

GARCH

Volatility persistence

0.8455
69.23***
∑γi Spline Coefficients
K=1
γ10.0000
0.38

Persistence:

0.967

Half-life:

21 days