V-Lab
Ibovespa Brasil Sao Paulo Stock Exchange Index AGARCH Volatility Analysis
Volatility prediction for Monday, September 21st, 2026
1 Day
16.99%
decreased by 0.17%
1 Week
17.30%
increased by 0.14%
1 Month
18.46%
increased by 1.30%
Analysis last updated: Friday, September 18, 2026 at 09:40 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 2, 1990 to Sep 18, 2026Model Insight
With persistence 0.997, volatility shocks have a half-life of 255 trading days (~1.0 years), close to a unit root, so long-run forecasts are highly sensitive to this estimate.
Asymmetry: negative returns raise volatility more
σ
AGARCH Model
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High persistence: persistence 0.997, shock half-life ~255 daysAsymmetry: negative returns raise volatility more
| Param | Value | t-stat |
|---|---|---|
| ωconst | 0.0100 | 0.96 |
| αARCH | 0.0646 | 6.93*** |
| βGARCH | 0.9327 | 93.37*** |
| γleverage | 0.4672 | 3.71*** |
0.997
Persistence255d
Half-lifeσ
AGARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0100 | 0.96 |
α ARCH Response to squared shocks | 0.0646 | 6.93*** |
β GARCH Volatility persistence | 0.9327 | 93.37*** |
γ leverage Additional response to negative shocks | 0.4672 | 3.71*** |
Persistence:
0.997
Half-life:
255 days
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