V-Lab
Tokyo Stock Exchange Tokyo Stock Price Index TOPIX Spline-GARCH Volatility Analysis
Volatility prediction for Friday, September 11th, 2026
1 Day
16.61%
decreased by 0.99%
1 Week
16.82%
decreased by 0.78%
1 Month
17.48%
decreased by 0.12%
Analysis last updated: Friday, September 11, 2026 at 05:40 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 2, 1990 to Sep 7, 2026Model 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 20 trading days.
τ
Spline-GARCH Model
Tap to view equation
Time-varying baseline: volatility reverts to a slowly-shifting spline trend
| Param | Value | t-stat |
|---|---|---|
| ωconst | 1.0044 | 9.85*** |
| αARCH | 0.1214 | 10.27*** |
| βGARCH | 0.8446 | 68.40*** |
Spline Coefficients
K=1
| γ1 | -0.0002 | -0.52 |
0.966
Persistence20d
Half-lifeτ
Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 1.0044 | 9.85*** |
α ARCH Response to squared shocks | 0.1214 | 10.27*** |
β GARCH Volatility persistence | 0.8446 | 68.40*** |
Spline Coefficients
K=1
| γ1 | -0.0002 | -0.52 |
Persistence:
0.966
Half-life:
20 days
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