Ibovespa Brasil Sao Paulo Stock Exchange Index Zero Slope Spline-GARCH Volatility Analysis
Volatility prediction for Monday, October 26th, 2026
1 Day
22.64%
decreased by 1.02%
1 Week
22.49%
decreased by 1.17%
1 Month
22.00%
decreased by 1.66%
Analysis last updated: Friday, October 23, 2026 at 09:26 PM UTC
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News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 2, 1990 to Oct 23, 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
Zero Slope Spline-GARCH Model
Tap to view equation
Time-varying baseline: volatility reverts to a slowly-shifting spline trend
| Param | Value | t-stat |
|---|---|---|
| ωconst | 4.5948 | 5.95*** |
| αARCH | 0.0842 | 7.88*** |
| βGARCH | 0.8823 | 71.31*** |
Spline Coefficients
K=4
| γ1 | 0.0348 | 5.42*** |
| γ2 | -0.0372 | -4.25*** |
| γ3 | 0.0025 | 0.52 |
| γ4 | 0.0021 | 0.67 |
0.967
Persistence20d
Half-lifeτ
Zero Slope Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 4.5948 | 5.95*** |
α ARCH Response to squared shocks | 0.0842 | 7.88*** |
β GARCH Volatility persistence | 0.8823 | 71.31*** |
Spline Coefficients
K=4
| γ1 | 0.0348 | 5.42*** |
| γ2 | -0.0372 | -4.25*** |
| γ3 | 0.0025 | 0.52 |
| γ4 | 0.0021 | 0.67 |
Persistence:
0.967
Half-life:
20 days
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