V-Lab
PSI 20 Portuguese Stock Index EGARCH Volatility Analysis
Volatility prediction for Friday, September 18th, 2026
1 Day
14.04%
increased by 0.77%
1 Week
14.27%
increased by 1.00%
1 Month
15.03%
increased by 1.76%
Analysis last updated: Thursday, September 17, 2026 at 05:48 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Dec 30, 1992 to Sep 11, 2026Model Insight
This asset exhibits a notable leverage effect: negative returns increase next-day volatility 72% more than equivalent positive returns.
σ
EGARCH Model
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Leverage: Negative returns increase volatility 72% more than positive returns
| Param | Value | t-stat |
|---|---|---|
| ωconst | 0.0080 | 1.80* |
| αARCH | 0.2351 | 13.87*** |
| βGARCH | 0.9661 | 207.00*** |
| γleverage | -0.0624 | -4.06*** |
0.966
Persistence20d
Half-lifeσ
EGARCH Model
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| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0080 | 1.80* |
α ARCH Response to squared shocks | 0.2351 | 13.87*** |
β GARCH Volatility persistence | 0.9661 | 207.00*** |
γ leverage Additional response to negative shocks | -0.0624 | -4.06*** |
Persistence:
0.966
Half-life:
20 days
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