Market Efficiency, Roughness and Long Memory in PSI20 Index Returns: Wavelet and Entropy Analysis

In this study, features of the financial returns of the PSI20index, related to market efficiency, are captured using wavelet- and entropy-based techniques. This characterization includes the following points. First, the detection of long memory, associated with low frequencies, and a global measure...

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Main Authors: Rui Pascoal, Ana Margarida Monteiro
Format: Article
Language:English
Published: MDPI AG 2014-05-01
Series:Entropy
Subjects:
Online Access:http://www.mdpi.com/1099-4300/16/5/2768
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author Rui Pascoal
Ana Margarida Monteiro
author_facet Rui Pascoal
Ana Margarida Monteiro
author_sort Rui Pascoal
collection DOAJ
description In this study, features of the financial returns of the PSI20index, related to market efficiency, are captured using wavelet- and entropy-based techniques. This characterization includes the following points. First, the detection of long memory, associated with low frequencies, and a global measure of the time series: the Hurst exponent estimated by several methods, including wavelets. Second, the degree of roughness, or regularity variation, associated with the H¨older exponent, fractal dimension and estimation based on the multifractal spectrum. Finally, the degree of the unpredictability of the series, estimated by approximate entropy. These aspects may also be studied through the concepts of non-extensive entropy and distribution using, for instance, the Tsallis q-triplet. They allow one to study the existence of efficiency in the financial market. On the other hand, the study of local roughness is performed by considering wavelet leader-based entropy. In fact, the wavelet coefficients are computed from a multiresolution analysis, and the wavelet leaders are defined by the local suprema of these coefficients, near the point that we are considering. The resulting entropy is more accurate in that detection than the H¨older exponent. These procedures enhance the capacity to identify the occurrence of financial crashes.
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spelling doaj.art-dfe23742ba43419da18d0ac8f19672ec2022-12-22T04:25:11ZengMDPI AGEntropy1099-43002014-05-011652768278810.3390/e16052768e16052768Market Efficiency, Roughness and Long Memory in PSI20 Index Returns: Wavelet and Entropy AnalysisRui Pascoal0Ana Margarida Monteiro1School of Economics, University of Coimbra, Avenida Doutor Dias da Silva 165, 3004-512 Coimbra, Coimbra, PortugalSchool of Economics, University of Coimbra, Avenida Doutor Dias da Silva 165, 3004-512 Coimbra, Coimbra, PortugalIn this study, features of the financial returns of the PSI20index, related to market efficiency, are captured using wavelet- and entropy-based techniques. This characterization includes the following points. First, the detection of long memory, associated with low frequencies, and a global measure of the time series: the Hurst exponent estimated by several methods, including wavelets. Second, the degree of roughness, or regularity variation, associated with the H¨older exponent, fractal dimension and estimation based on the multifractal spectrum. Finally, the degree of the unpredictability of the series, estimated by approximate entropy. These aspects may also be studied through the concepts of non-extensive entropy and distribution using, for instance, the Tsallis q-triplet. They allow one to study the existence of efficiency in the financial market. On the other hand, the study of local roughness is performed by considering wavelet leader-based entropy. In fact, the wavelet coefficients are computed from a multiresolution analysis, and the wavelet leaders are defined by the local suprema of these coefficients, near the point that we are considering. The resulting entropy is more accurate in that detection than the H¨older exponent. These procedures enhance the capacity to identify the occurrence of financial crashes.http://www.mdpi.com/1099-4300/16/5/2768efficiencylong memoryfractal dimensionunpredictabilityq-tripletentropywavelets
spellingShingle Rui Pascoal
Ana Margarida Monteiro
Market Efficiency, Roughness and Long Memory in PSI20 Index Returns: Wavelet and Entropy Analysis
Entropy
efficiency
long memory
fractal dimension
unpredictability
q-triplet
entropy
wavelets
title Market Efficiency, Roughness and Long Memory in PSI20 Index Returns: Wavelet and Entropy Analysis
title_full Market Efficiency, Roughness and Long Memory in PSI20 Index Returns: Wavelet and Entropy Analysis
title_fullStr Market Efficiency, Roughness and Long Memory in PSI20 Index Returns: Wavelet and Entropy Analysis
title_full_unstemmed Market Efficiency, Roughness and Long Memory in PSI20 Index Returns: Wavelet and Entropy Analysis
title_short Market Efficiency, Roughness and Long Memory in PSI20 Index Returns: Wavelet and Entropy Analysis
title_sort market efficiency roughness and long memory in psi20 index returns wavelet and entropy analysis
topic efficiency
long memory
fractal dimension
unpredictability
q-triplet
entropy
wavelets
url http://www.mdpi.com/1099-4300/16/5/2768
work_keys_str_mv AT ruipascoal marketefficiencyroughnessandlongmemoryinpsi20indexreturnswaveletandentropyanalysis
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