V-Lab
Tokyo Stock Exchange Tokyo Stock Price Index TOPIX GAS-GARCH Student T Volatility Analysis
Volatility prediction for Friday, July 24th, 2026
1 Day
21.15%
decreased by 1.13%
1 Week
21.12%
decreased by 1.16%
1 Month
21.01%
decreased by 1.27%
Analysis last updated: Friday, July 24, 2026 at 05:42 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 2, 1990 to Jul 17, 2026Model 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
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 1.6542 | 11.76*** |
α ARCH Response to squared shocks | 0.0831 | 38.65*** |
β GARCH Volatility persistence | 0.9785 | 515.81*** |
ν DF Student-t tail thickness | 6.3575 | 8.14*** |
Persistence:
0.978
Half-life:
32 days
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