V-Lab
Ibovespa Brasil Sao Paulo Stock Exchange Index Spline-GARCH Volatility Analysis
Volatility prediction for Monday, September 28th, 2026
1 Day
13.76%
decreased by 0.51%
1 Week
13.85%
decreased by 0.42%
1 Month
14.15%
decreased by 0.12%
Analysis last updated: Friday, September 25, 2026 at 10:35 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 2, 1990 to Sep 25, 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 | 4.5750 | 6.03*** |
| αARCH | 0.0823 | 7.91*** |
| βGARCH | 0.8838 | 72.79*** |
Spline Coefficients
K=4
| γ1 | 0.0361 | 5.66*** |
| γ2 | -0.0405 | -4.64*** |
| γ3 | 0.0088 | 1.62 |
| γ4 | -0.0150 | -1.70* |
0.966
Persistence20d
Half-lifeτ
Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 4.5750 | 6.03*** |
α ARCH Response to squared shocks | 0.0823 | 7.91*** |
β GARCH Volatility persistence | 0.8838 | 72.79*** |
Spline Coefficients
K=4
| γ1 | 0.0361 | 5.66*** |
| γ2 | -0.0405 | -4.64*** |
| γ3 | 0.0088 | 1.62 |
| γ4 | -0.0150 | -1.70* |
Persistence:
0.966
Half-life:
20 days
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