scholarly journals Efficiency of Asean-5 Markets: An Detrended Fluctuation Analysis

2020 ◽  
Vol 12 (2) ◽  
pp. 13-19
Author(s):  
Rui Dias ◽  
Paula Heliodoro ◽  
Paulo Alexandre
Keyword(s):  
Random Walk ◽  
Financial Markets ◽  
Stock Prices ◽  
Detrended Fluctuation Analysis ◽  
Abnormal Returns ◽  
Weak Form ◽  
The Philippines ◽  
Fluctuation Analysis ◽  
Chinese Market ◽  
Detrended Fluctuation

This study intends to analyse efficiency, in its weak form, in the financial markets of Indonesia, Malaysia, Philippines, Singapore, Thailand (ASEAN-5), and China, during the global pandemic (Covid-19). Different approaches have been undertaken to carry out this analysis in order to determine whether: (i) ASEAN-5 financial markets and China are efficient, in their weak form, during the analysis period? The results indicate that the random walk hypothesis is rejected in all markets. The values of the variance ratios are, in all cases, lower than the unit, which implies that the returns are autocorrelated over time and, there is a reversion to the average, in all indices. In corroboration, the exponents Detrended Fluctuation Analysis (DFA), indicate significant long memories with a larger incidence in the Philippines and Singapore markets, however the Chinese market evidences anti persistence. These results demonstrate that stock prices do not completely reflect the available information and that stock prices movements are not i.i.d. This has implications for investors, as some returns can be expected, creating opportunities for arbitrage and abnormal returns, contrary to the assumptions of random walk and information efficiency. These conclusions also allow market regulators to implement measures to ensure better information in these regional markets.

scholarly journals Testing financial market efficiency

2014 ◽  
Vol 3 (3) ◽  
pp. 351-372
Author(s):  
Islem Ahmed Boutabba
Keyword(s):  
Random Walk ◽  
Financial Markets ◽  
Stock Prices ◽  
Abnormal Returns ◽  
Weak Form ◽  
Efficient Market Hypothesis ◽  
Central Hypothesis ◽  
Excess Volatility ◽  
Fama And French ◽  
Efficiency Hypothesis

Since the birth of the financial literature until the 1970s, the efficient market hypothesis has been regarded as a central hypothesis. In the mid-1970s, there were theoretical and empirical evidence stating that the EMH seems untouchable. However, recently there has been an emergence of arguments doubting the EMH. The EMH implicitly indicates that stock prices can follow a random walk. Currently, financial theory has shown that stock prices do not follow a random walk.In this regard, our empirical study rejected the hypothesis of a random walk for 27 indices out of 28 studied. We confirm that the studied indices time series do not follow a random walk, and therefore we reject the financial markets efficiency hypothesis in its weak form. This result corroborates those of Fama and French (1992.993), DeBondt and Thaler (1985), Lo and MacKinlay (1991), Jagadeesh and Titman (1993) and Shleifer and Vishny (1997). Therefore, financial markets efficiency hypothesis in its weak form is also rejected. This result is logical given the limited capacity of the classical theory in explaining abnormal returns such as bubbles, crashes and excess volatility

scholarly journals Testing financial market efficiency

2014 ◽  
Vol 4 (2) ◽  
pp. 548-563
Author(s):  
Islem Boutabba
Keyword(s):  
Random Walk ◽  
Financial Markets ◽  
Stock Prices ◽  
Abnormal Returns ◽  
Weak Form ◽  
Efficient Market Hypothesis ◽  
Central Hypothesis ◽  
Excess Volatility ◽  
Fama And French ◽  
Efficiency Hypothesis

Since the birth of the financial literature until the 1970s, the efficient market hypothesis has been regarded as a central hypothesis. In the mid-1970s, there were theoretical and empirical evidence stating that the EMH seems untouchable. However, recently there has been an emergence of arguments doubting the EMH. The EMH implicitly indicates that stock prices can follow a random walk. Currently, financial theory has shown that stock prices do not follow a random walk. In this regard, our empirical study rejected the hypothesis of a random walk for 27 indices out of 28 studied. We confirm that the studied indices time series do not follow a random walk, and therefore we reject the financial markets efficiency hypothesis in its weak form. This result corroborates those of Fama and French (1992.993), DeBondt and Thaler (1985), Lo and MacKinlay (1991), Jagadeesh and Titman (1993) and Shleifer and Vishny (1997). Therefore, financial markets efficiency hypothesis in its weak form is also rejected. This result is logical given the limited capacity of the classical theory in explaining abnormal returns such as bubbles, crashes and excess volatility.

scholarly journals TESTING THE EMPIRICS OF WEAK FORM OF EFFICIENT MARKET HYPOTHESIS: EVIDENCE FROM LAC REGION MARKETS

2020 ◽  
Author(s):  
Hortense Santos ◽  
◽  
Rui Dias ◽  
Paula Heliodoro ◽  
Paulo Alexandre ◽  
...  
Keyword(s):  
Random Walk ◽  
Financial Markets ◽  
Weak Form ◽  
Fluctuation Analysis ◽  
Linear Component ◽  
Test Results ◽  
Random Walk Hypothesis ◽  
Regional Markets ◽  
Two Samples ◽  
Non Linear

The new coronavirus disease (Covid-19) evolved quickly from a regional health outbreak to a global collapse, stopping the global economy in a unprecedented way, creating uncertainty and chaos in the financial markets. Based on these events, it is intended in this paper to test the persistence of profitability in the financial markets of Argentina, Brazil, Chile, Colombia, Peru and Mexico, in the period between January 2018 to July 2020. In order to perform this analysis where undertaken different approaches in order to analyze if: (i) the financial markets of Latin America are efficient in their weak-form during the global pandemic (Covid-19)? ii) If so, the persistent long memories cause risks between these regional markets? The results suggest that the returns don’t follow the i.i.d. hypothesis, from dimension 2, reinforcing the idea that returns of stock indexes have a non-linear nature or a significant non-linear component, exception made to the Argentina market, which was expected in virtue of the Ljung-Box (with the return squares) test results, and ARCH-LM. Corroborating the exponents Detrended Fluctuation Analysis (DFA), indicate the presence of persistent long memories, namely into the following markets: Colombia (0.72), Chile (0.66), Brazil (0.58) and Peru (0.57). The Argentina market does not reject the random walk hypothesis, while the Mexican market suggests some anti-persistence (0.41). This situation has implications for investors, once that some returns can be expected, creating arbitration opportunities and abnormal income, contrary to the supposed from the random walk hypothesis and information efficiency. The t-test results of the heteroscedasticity form the two samples suggest that there is no risk transmission between these regional markets, with the exception to the BOVESPA / BOLSAA MX markets, that is, the existence of persistent long memories in the returns does not imply the risk transmission between markets. These finds allow the creation of strategies of diversification inefficient portfolios. These conclusions also open space for the market regulators to implement measures that guarantee a better informational information of these regional markets.

Testing the Random Walk Hypothesis for Real Exchange Rates

2021 ◽  
pp. 304-322
Author(s):  
Rui Teixeira Dias ◽  
Pedro Pardal ◽  
Hortense Santos ◽  
Cristina Vasco
Keyword(s):  
Exchange Rates ◽  
Detrended Fluctuation Analysis ◽  
Real Exchange Rates ◽  
Weak Form ◽  
Fluctuation Analysis ◽  
Random Walk Hypothesis ◽  
Variance Ratios ◽  
Exchange Markets ◽  
Detrended Fluctuation ◽  
Over Time

This chapter aims to analyze the efficiency, in its weak form, in the exchange rates of Brazil vs. USA, Australia, Canada, Europe (Euro Zone), Switzerland, United Kingdom, and Japan from July 1, 2019 to September 20, 2020. The results suggest that exchange rates show signs of (in)efficiency, in their weak form (i.e., the values of the variance ratios are lower than the unit), which implies that returns are autocorrelated over time, and there is reversal to the average. In corroboration, the results of detrended fluctuation analysis (DFA) show persistence in yields (i.e., the existence of long memories), thus validating the results of the Lo and Mackinlay model that show autocorrelation between the series of yields. As a conclusion, the authors show that the assumption of market efficiency may be questioned, since the forecast of market movement may be improved if the lagged movements of the other markets are taken into account, allowing the occurrence of arbitrage operations in these foreign exchange markets.

scholarly journals TESTING THE EMPIRICS OF WEAK FORM OF EFFICIENT MARKET HYPOTHESIS: EVIDENCE FROM LAC REGION MARKETS

2020 ◽  
Author(s):  
Hortense Santos ◽  
◽  
Rui Dias ◽  
Paula Heliodoro ◽  
Paulo Alexandre ◽  
...  
Keyword(s):  
Random Walk ◽  
Financial Markets ◽  
Weak Form ◽  
Fluctuation Analysis ◽  
Linear Component ◽  
Test Results ◽  
Random Walk Hypothesis ◽  
Regional Markets ◽  
Two Samples ◽  
Non Linear

The new coronavirus disease (Covid-19) evolved quickly from a regional health outbreak to a global collapse, stopping the global economy in a unprecedented way, creating uncertainty and chaos in the financial markets. Based on these events, it is intended in this paper to test the persistence of profitability in the financial markets of Argentina, Brazil, Chile, Colombia, Peru and Mexico, in the period between January 2018 to July 2020. In order to perform this analysis where undertaken different approaches in order to analyze if: (i) the financial markets of Latin America are efficient in their weak-form during the global pandemic (Covid-19)? ii) If so, the persistent long memories cause risks between these regional markets? The results suggest that the returns don’t follow the i.i.d. hypothesis, from dimension 2, reinforcing the idea that returns of stock indexes have a non-linear nature or a significant non-linear component, exception made to the Argentina market, which was expected in virtue of the Ljung-Box (with the return squares) test results, and ARCH-LM. Corroborating the exponents Detrended Fluctuation Analysis (DFA), indicate the presence of persistent long memories, namely into the following markets: Colombia (0.72), Chile (0.66), Brazil (0.58) and Peru (0.57). The Argentina market does not reject the random walk hypothesis, while the Mexican market suggests some anti-persistence (0.41). This situation has implications for investors, once that some returns can be expected, creating arbitration opportunities and abnormal income, contrary to the supposed from the random walk hypothesis and information efficiency. The t-test results of the heteroscedasticity form the two samples suggest that there is no risk transmission between these regional markets, with the exception to the BOVESPA / BOLSAA MX markets, that is, the existence of persistent long memories in the returns does not imply the risk transmission between markets. These finds allow the creation of strategies of diversification inefficient portfolios. These conclusions also open space for the market regulators to implement measures that guarantee a better informational information of these regional markets.

How fast do stock prices adjust to market efficiency? Evidence from a detrended fluctuation analysis

2013 ◽  
Vol 392 (7) ◽  
pp. 1631-1637 ◽  
Author(s):  
Juan C. Reboredo ◽  
Miguel A. Rivera-Castro ◽  
José G.V. Miranda ◽  
Raquel García-Rubio
Keyword(s):  
Market Efficiency ◽  
Stock Prices ◽  
Detrended Fluctuation Analysis ◽  
Fluctuation Analysis ◽  
Detrended Fluctuation
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