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 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 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.

An Empirical Study on Efficient Market Hypothesis with reference to FMCG Sector

GIS Business ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. 109-126
Author(s):  
Nitin Tanted ◽  
Prashant Mistry
Keyword(s):  
Stock Prices ◽  
Stock Price ◽  
Abnormal Returns ◽  
Weak Form ◽  
Efficient Market Hypothesis ◽  
Controversial Issues ◽  
Efficient Market ◽  
Price Movements ◽  
Run Test ◽  
Stock Price Movements

One of the highly controversial issues in the area of finance is “Efficient Market Hypothesis”. Efficient Market Hypothesis states that, “In an efficient market, all available price information is reflected in the stock prices and it is not possible to generate abnormal returns compared to other investors.” A lot of studies conducted previouslyto test the Efficient Market Hypothesis, confirmed the theory until recent years, when some academicians found it to be non-applicable in financial markets. According to them, it is possible to forecast the stock price movements using Technical Analysis. The results of various studies have been inconclusive and indefinite about the issue. This study attempted to test the efficiency of FMCG Sector stocks in India in its weak form. For the study, closing prices of top 10 stocks from Nifty FMCG index has been taken for the 5-year period ranging from 1st October 2014 to 30th September 2019. Wald-Wolfowitz Run test has been used to test the haphazard movements in the stock price movements. The results indicated that FMCG sector stocks does support the Efficient Market Hypothesis and exhibit efficiency in its weak form. Hence, it is not possible to accurately predict the price movements of these stocks.

scholarly journals Random Walk Hypothesis for Stock Prices in Fiji

2021 ◽  
Vol 13 (2) ◽  
pp. 79-88
Author(s):  
Janesh Sami
Keyword(s):  
Random Walk ◽  
Stock Market ◽  
Unit Root ◽  
Stock Prices ◽  
Structural Break ◽  
Weak Form ◽  
Efficient Market Hypothesis ◽  
Random Walk Hypothesis ◽  
Augmented Dickey Fuller ◽  
Historical Movement

The main goal of this paper is to investigate the random walk hypothesis in Fiji using monthly data from January 2000 to October 2017. Applying augmented Dickey Fuller (ADF 1979, 1981) and Phillips-Perron (1988), Zivot-Andrews (1992), and Narayan and Popp (2010) unit root tests, this study finds that stock prices is best characterized as non-stationary. The estimated multiple structural break dates in the stock prices corresponds with devaluation of Fijian dollar by 20 percent in 2009 and General Elections in September 2014, which Fiji First Party won by majority votes. The empirical results indicate that stock prices are best characterized as a unit root (random walk) process, indicating that the weak-form efficient market hypothesis holds in Fiji’s stock market. Hence, it will be difficult to predict future returns based on historical movement of stock prices in Fiji’s stock market.

scholarly journals Weak Form Efficiency of the Amman Stock Exchange: An Empirical Analysis (2000-2013)

2015 ◽  
Vol 11 (1) ◽  
pp. 173 ◽  
Author(s):  
Izz eddien N. Ananzeh
Keyword(s):  
Financial Markets ◽  
Stock Returns ◽  
Stock Prices ◽  
Stock Exchange ◽  
Weak Form ◽  
Efficient Market Hypothesis ◽  
Final Conclusion ◽  
Clear Cut ◽  
Amman Stock Exchange ◽  
Daily Returns

<p>The Efficient Market Hypothesis (EMH) has been a lot of debates in the literature of finance because of its important implication, and there is no clear-cut case regarding the efficiency of the financial markets for both developed and emerging markets. This empirical study conducted to examine EMH at the weak form level of Amman stock Exchange (ASE) by using daily observations for the period span from 2000 to 2013. Recent econometric procedures utilized for testing the randomness of stock prices for ASE. The results of serial correlation reject the existence of random walks in daily returns of the ASE, and the unit root tests also conclude the return series of ASE are stationary and inefficient at the weak-level. Also the runs tests verify that the stock returns series on ASE are not random, and our final conclusion reports that the ASE is inefficient at the weak form level. </p>

scholarly journals EFIKASNOST FINANSIJSKIH TRŽIŠTA / EFFICIENCY OF FINANCIAL MARKETS

2016 ◽  
Vol 11 (1) ◽  
Author(s):  
Predrag Kapor
Keyword(s):  
Financial Markets ◽  
Behavioral Finance ◽  
Stock Prices ◽  
Global Financial Crisis ◽  
Weak Form ◽  
Efficient Market Hypothesis ◽  
Strong Form ◽  
The Status ◽  
Finance Theory ◽  
Available Information

Are financial markets efficient is a question on which there is still no clear and complete answer. Position that prices of securities fully reflect available information about securities is called the efficient market hypothesis (EMH). The EMH (on the example of stocks) has three forms (or levels) of efficiency: 1) the ‘’ weak’’ form of the EMH- is the claim that stock prices reflect all information contained in previous transactions; 2) the ‘’ semi- strong’’ form of the EMH- is the claim that stock prices reflect all publicly available information, and 3) the’’ strong’’ form of the EMH- is the claim that stock prices reflect all relevant information (public and private), including the privileged (the insider) information.Numerous studies have confirmed the existence of a’’ weak’’ form of the EMH, and generally supported the existence of a’’ semi-strong’’ form of the EMH, but not of a ‘’ strong’’ form of the EMH. However, the EMH, even if it is a ‘’weak’’ or a ‘’semi-strong’’ form has a number of weaknesses. Some of the the EMH assumptions confront with the reality – there is no perfect information, transaction and information costs can be significant, markets are often imperfect, and investors do not have complete knowledge about the set of all available financial strategies for a given situation.The information ’’overload’’ confuses people and affects their ability to prioritize and make good decisions. On the other hand, electronic trading method significantly affects the information at the disposal of the different market actors. It seems that the greatest threat to the EMH comes from the field of behavioral finance, which is engaged in research on the possible impact of psychological factors (loss aversion, anchoring, overconfidence...) on the behavior of investors. The basic argument of behavioral finance is that ’’standard’’ financial theory is not paying attention to how ordinary people make decisions and that ‘’ human factor’’ can not be ignored.Tha aim of this study was to critically examine the EMH. Apperently, the EMH after numerous studes and identified anomalies, largely remains at the level of (insufficiently confirmed) hypothesis, although it is often given the status, or created an illusion, of confirmed. This is also because the EMH is an important component of the rulling ’’paradigm’’ in finance or ’’standard finance theory’’. Joperdizing the status of the EMH bring into question many other important components of this ’’paradigm’’.The EMH has not offered acceptable answers to some of the specific developments and events in the financial market, including the last global financial crisis. But, the EMH still remains one of the cornerstones of ’’standard’’ finance theory.

scholarly journals A Test of Return Predictability in the Vietnamese Stock Market

2020 ◽  
Vol 11 (2) ◽  
pp. 390
Author(s):  
Thanh Trung Le ◽  
Anh Tram Luong
Keyword(s):  
Random Walk ◽  
Stock Market ◽  
Stock Prices ◽  
Weak Form ◽  
Efficient Market Hypothesis ◽  
Return Predictability ◽  
Emerging Countries ◽  
Market Volatility ◽  
Stock Market Volatility ◽  
First Time

For the first time, the market efficiency is examined in the different context of the stock market. By employing tests of weak-form efficiency, this study finds out that the overall, Vietnamese stock market does not follow a random walk regardless of the degree of stock market volatility. Therefore, technical analysis could be used by investors and financial managers to forecast price and gain profits on the market. Another finding is that although the Vietnamese market is not weak-form efficient, there is an improvement in recent years. The paper suggests that if investors and financial managers can employ past returns to predict stock prices and make decisions on the Vietnamese market, they should change their strategies in the future. This finding also contributes to studies on the Efficient Market Hypothesis in emerging countries and its performance in different economic contexts.

scholarly journals STOCK MARKET EFFICIENCY IN AFRICA: EVIDENCE FROM RANDOM WALK HYPOTHESIS

2020 ◽  
Author(s):  
Rui Dias ◽  
◽  
Hortense Santos ◽  
Keyword(s):  
Random Walk ◽  
Financial Markets ◽  
Stock Markets ◽  
Weak Form ◽  
Efficient Market Hypothesis ◽  
Random Walk Hypothesis ◽  
Global Pandemic ◽  
Stock Market Efficiency ◽  
Variance Ratios ◽  
The Mean

This paper aims to test the efficient market hypothesis, in its weak form, in the stock markets of BOTSWANA, EGYPT, KENYA, MOROCCO, NIGERIA and SOUTH AFRICA, in the period from September 2, 2019 to September 2, 2020. In order to achieve this analysis, we intend to find out if: the global pandemic (Covid-19) has decreased the efficiency, in its weak form, of African stock markets? The results therefore support the evidence that the random walk hypothesis is not supported by the financial markets analyzed in this period of global pandemic. The values of variance ratios are lower than the unit, which implies that the yields are autocorrelated in time and, there is reversal to the mean, and no differences were identified between the stock markets analyzed. The authors consider that the results achieved are of interest to investors looking for opportunities for portfolio diversification in these regional stock markets.

scholarly journals Random walks and market efficiency tests: evidence on US, Chinese and European capital markets within the context of the global Covid-19 pandemic

2020 ◽  
Vol 11 (4) ◽  
pp. 585-608
Author(s):  
Rui Dias ◽  
Nuno Teixeira ◽  
Veronika Machova ◽  
Pedro Pardal ◽  
Jakub Horak ◽  
...  
Keyword(s):  
Random Walk ◽  
Market Efficiency ◽  
Capital Markets ◽  
Global Economy ◽  
Structural Breaks ◽  
Abnormal Returns ◽  
Value Added ◽  
Weak Form ◽  
Efficient Market Hypothesis ◽  
Random Walk Hypothesis

Research background: Covid-19 has affected the global economy and has had an inevitable impact on capital markets. In the week of February 24?28, 2020, stock markets crashed. The index FTSE 100 decreased 13%, while the indices DJIA and S&P 500 fell 11?12%, the biggest drop since the 2007?2008 financial and economic crisis. It is therefore of interest to test the random walk hypothesis in developed capital markets, European and also non-European, in order to understand the different predictabilities between them. Purpose of the article: The aim is to analyze capital market efficiency, in its weak form, through the stock market indices of Belgium (index BEL 20), France (index CAC 40), Germany (index DAX 30), USA (index DOW JONES), Greece (index FTSE Athex 20), Spain (index IBEX 35), Ireland (index ISEQ), Portugal (index PSI 20) and China (index SSE) for the period from December 2019 to May 2020. Methods: Panel unit root tests of Breitung (2000), Levin et al. (2002) and Hadri (2002) were used to assess the time series stationarity. The test of Clemente et al. (1998) is used to detect structural breaks. The tests for the random walk hypothesis follows the variance ratio methodology proposed by Lo and MacKinlay (1988). Findings & Value added: In general, we found mixed confirmation about the EMH (efficient market hypothesis). Taking into account the conclusions of the rank variance test, the random walk hypothesis was rejected in the case of stock indices: Dow Jones, SSE and PSI 20, partially rejected in the case indices: BEL 20, CAC 40, FTSTE Athex 20 and DEX 30, but accepted for indices: IBEX 35 and ISEQ. The results also show that prices do not fully reflect the information available and that changes in prices are not independent and identically distributed. This situation has consequences for investors, since some returns can be expected, creating opportunities for arbitrage and for abnormal returns, contrary to the assumptions of random walk and information efficiency.

An investigation of time varying market efficiency: evidence from STOXX Europe Christian index

2021 ◽  
Vol 37 (4) ◽  
pp. 631-643
Author(s):  
Tayyaba Yousaf ◽  
Sadia Farooq ◽  
Ahmed Muneeb Mehta
Keyword(s):  
Price Index ◽  
Abnormal Returns ◽  
Weak Form ◽  
Efficient Market Hypothesis ◽  
Time Varying ◽  
Content Type ◽  
Daily Data ◽  
New Information ◽  
Academic Researchers ◽  
The Impact

Purpose The purpose of this study is to investigate whether the STOXX Europe Christian price index (SECI) follows the premise of efficient market hypothesis (EMH). Design/methodology/approach The study used daily data of SECI for the period of 15 years as its launch date i.e. 31 December 2004 to 31 December 2019. Data are analyzed by taking a full-length sample and fixed-length subsample. For subsample, the data are divided into five subsamples of three years each. Subsample analysis is important for analyzing time varying efficiency of the series, as the market is said to follow EMH if it is being efficient throughout the sample. Both type of samples is examined through linear tests including autocorrelations test and variance ratio (VR) test. Findings Tests applied conclude that SECI is weak-form efficient, which means that the prices of the index include all the relevant past information and immediately react to new information. Hence, the investors cannot earn abnormal returns. Originality/value Religion-based indices grasped the attention of investors, policymakers and academic researchers because of increased concern over ethics in business. Though the impact of religion on the economy have been studied in many ways but the efficiency of religion-based indices have been less explored. The current study is primary in its nature as it analysis the efficiency of SECI. This index is important to explore because Christianity is the world’s top religion with 2.3 billion followers around the globe.

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