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V-Lab

PSI 20 Portuguese Stock Index AGARCH Volatility Analysis

Volatility prediction for Friday, October 30th, 2026

1 Day

13.29%

decreased by 0.09%

1 Week

13.58%

increased by 0.20%

1 Month

14.59%

increased by 1.21%

Analysis last updated: Thursday, October 29, 2026 at 06:04 PM UTC

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Date Range:

from

10/29/2024

to

10/29/2026

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of PSI 20 Portuguese Stock Index AGARCH

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Dec 30, 1992 to Oct 23, 2026

Model Insight

The news-impact curve is shifted (γ = 0.20) so that negative returns raise next-day volatility more than positive returns of the same size. The gap is largest for small shocks and narrows for larger ones.

σ

AGARCH Model

Tap to view equation

Asymmetry: negative returns raise volatility more
ParamValuet-stat
ωconst0.0211
5.28***
αARCH0.1289
12.69***
βGARCH0.8564
88.43***
γleverage0.1963
4.10***

0.985

Persistence

47d

Half-life
σ

AGARCH Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

0.0211
5.28***
α

ARCH

Response to squared shocks

0.1289
12.69***
β

GARCH

Volatility persistence

0.8564
88.43***
γ

leverage

Additional response to negative shocks

0.1963
4.10***

Persistence:

0.985

Half-life:

47 days