V-Lab
Nikkei Stock Average Volatility Index GAS-GARCH Student T Volatility Analysis
Volatility prediction for Monday, August 3rd, 2026
1 Day
108.83%
decreased by 14.59%
1 Week
107.77%
decreased by 15.65%
1 Month
104.88%
decreased by 18.54%
Analysis last updated: Friday, August 7, 2026 at 08:40 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 3, 1990 to Jul 31, 2026Model Insight
Volatility shocks decay with a half-life of 10 trading days, meaning a shock loses half its impact after approximately 10 days. Returns follow a Student-t distribution with v = 4.61 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 | 39.4817 | 13.10*** |
α ARCH Response to squared shocks | 0.1215 | 29.13*** |
β GARCH Volatility persistence | 0.9350 | 195.61*** |
ν DF Student-t tail thickness | 4.6148 | 10.41*** |
Persistence:
0.935
Half-life:
10 days
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