scholarly journals Weak Form Market Efficiency of the Johannesburg Stock Exchange: Pre, During and Post the 2008 Global Financial Crisis

2017 ◽  
Vol 9 (5) ◽  
pp. 29 ◽  
Author(s):  
Olwetu Fusthane ◽  
Kapingura F M

The importance of the efficiency of the stock market cannot be underestimated, given the critical role the stock market plays through brings together those who demand and supply development finance. It is against this background that this study focused on analysing the weak form efficiency of the Johannesburg Stock Exchange for the period 2005 to 2016 utilising several methodologies which include unit root tests, autocorrelation test and variance ratio. The empirical results from unit root tests indicated that the null hypothesis of a random walk could not be rejected. The same also applied to the autocorrelation test and variance ratio test except for a few instances. Thus irrespective of the few instances which represent the inefficiency of the market, to a greater extent there is evidence of the market being weak form efficient. Thus even though the work done towards ensuring that the market is efficient is commendable, there is need to ensure that further steps are taken to enhance the efficiency of the market. This is, to some extent suggest that investors are able to make abnormal profits from the market.   

2017 ◽  
Vol 9 (5(J)) ◽  
pp. 29-42
Author(s):  
Olwetu Fusthane ◽  
Kapingura F M

The importance of the efficiency of the stock market cannot be underestimated, given the critical role the stock market plays through brings together those who demand and supply development finance. It is against this background that this study focused on analysing the weak form efficiency of the Johannesburg Stock Exchange for the period 2005 to 2016 utilising several methodologies which include unit root tests, autocorrelation test and variance ratio. The empirical results from unit root tests indicated that the null hypothesis of a random walk could not be rejected. The same also applied to the autocorrelation test and variance ratio test except for a few instances. Thus irrespective of the few instances which represent the inefficiency of the market, to a greater extent there is evidence of the market being weak form efficient. Thus even though the work done towards ensuring that the market is efficient is commendable, there is need to ensure that further steps are taken to enhance the efficiency of the market. This is, to some extent suggest that investors are able to make abnormal profits from the market.   


2016 ◽  
Vol 11 (3) ◽  
pp. 75-86 ◽  
Author(s):  
Josephine Njuguna

The purpose of this article is to examine the efficiency of the Tanzania stock market. The study attempts to answer whether the Tanzania stock market is weak-form efficient. The study applies a battery of tests: the serial correlation test, unit root tests, runs test and the variance ratio test using daily and weekly data with a sample spanning from November 2006 to August 2015 for the Dar es Salaam Stock Exchange (DSE) all share index and from January 2009 to August 2015 for the DSE share index. Overall, the results of the market efficiency are mixed. The serial correlation test, unit root test and the runs test do not support weak-form efficiency, while the more robust variance ratio test supports weak-form efficiency for the DSE. The main contribution of the study is that the market efficiency of the Tanzania stock market has increased over the sample period. Keywords: adaptive market hypothesis, efficiency market hypothesis, serial correlations test, unit root test, runs test, variance ratio test, Dar es Salaam Stock Exchange. JEL Classification: G14, G15


Author(s):  
André Heymans ◽  
Leonard Santana

Background: There are various studies that confirm the efficiency of the Johannesburg Stock Exchange (JSE), implying that there are no opportunities for active portfolio managers to earn excess returns over the long run.Aim: The aim of the research is to prove that the sub-indices on the JSE go through cycles of efficiency and inefficiency even though the JSE as a whole might be considered informationally efficient.Setting: Although the JSE as a whole can be considered to be weak-form efficient, portfolio managers are not bound to investing in large liquid stocks alone. Many aggressive funds allow managers to also allocate a portion of their portfolio to smaller stocks. This has implications when considering the efficiency of the stocks being selected.Methods: Given the impact efficiency has on portfolio selection, we test for the adaptive market hypothesis using a representative sample of stock indices by means of the automatic variance ratio test, the Chow–Denning joint variance ratio and the joint sign test on the JSE.Results: Our results confirm that some of the smaller, and in some instances younger, indices are not always as efficient as the all share index, thus allowing portfolio managers with an active management approach some opportunities to profit from informational inefficiencies in the market.Conclusion: The practice of active management by portfolio managers in the South African market seems to defy logic if one considers the fact that the JSE as a whole is at the very least weak-form efficient. By proving that some of the sub-indices that make up the all share index are inefficient most of the time, this article shows that the phenomenon of active portfolio managers is less of a surprise.


2019 ◽  
Vol 12 (2) ◽  
pp. 81 ◽  
Author(s):  
Dzung Phan Tran Trung ◽  
Hung Pham Quang

This paper aims to test the adaptive market hypothesis in the two main Vietnamese stock exchanges, namely Ho Chi Minh City Stock Exchange (HSX) and Hanoi Stock Exchange (HNX), by measuring the relationship between current stock returns and historical stock returns. In particular, the tests employed are the automatic variance ratio test (“AVR”), the automatic portmanteau test (“AP”), the generalized spectral test (“GS”), and the time-varying autoregressive (TV-AR) approach. The empirical results validate the adaptive market hypothesis in the Vietnamese stock market. Furthermore, the results suggest that the evolution of HSX has served as an important factor of the adaptive market hypothesis.


2015 ◽  
Vol 4 (2) ◽  
pp. 79-90
Author(s):  
Md.‬ Abu Hasan‬‬‬‬‬‬‬‬

Measuring the efficiency of the stock market is an important research topic as there are various implications for investors. This paper investigates the weak form efficiency in the framework of the random walk hypothesis for the stock market in Bangladesh, employing both Non Parametric tests (Runs test and Phillips-Perron test) and Parametric tests (Autocorrelation test, Augmented Dickey-fuller test, and Variance Ratio test). The study uses daily return data for the three stock indices of Dhaka Stock Exchange such as DSI (from 02 January 1993 to 27 January 2013) with a total of 4823 daily return observations, DGEN (from 01 January 2002 to 31 July 2013) with a total of 2903 daily return observations, and DSE-20 (from 01 January 2001 to 27 January 2013) with a total of 3047 daily return observations. The evidence suggests that all the return series do not follow the random walk model, and thus the Dhaka Stock Exchange is inefficient in weak form. Thus, historical stock prices can be used to achieve superior gains from the stock markets in Bangladesh. JEL Classification Code: C22, G10, G14


2011 ◽  
Vol 2 (6) ◽  
pp. 249-257
Author(s):  
Muhammad Irfan ◽  
Maria Irfan .

This paper studies the performance of Karachi Stock Exchange (KSE) of Pakistan via nonparametric approaches. The study includes the weekly open and closing prices of KSE- 100 indexes for the period of 1st January 1999 to 31st August 2009. Several non-parametric approaches including KolmogorovSmirnov test (Lilliefors test), Ryan-Joiner test (Shapiro-Wilk), Anderson-Darling test, Phillips Perron (PP) unit root test and Runs test are used to test the conviction of the KSE stock market. All non-parametric tests graphically and numerically inform us that both return series do not follow the assumption of normality and randomness, which means rejecting the hypothesis of weak form of efficiency. Generally, results from the observed analysis strongly recommend that the Karachi Stock Market of Pakistan is not efficient.


2014 ◽  
Vol 13 (6) ◽  
pp. 1241 ◽  
Author(s):  
Tafadzwa T. Chitenderu ◽  
Andrew Maredza ◽  
Kin Sibanda

In this paper, we test the Johannesburg Stock Exchange market for the existence of the random walk hypothesis using monthly time series of the All Share Index (ALSI) covering the period 2000 2011. Traditional methods, such as unit root tests and autocorrelation test, were employed first and they all confirmed that during the period under consideration, the JSE price index followed the random walk process. In addition, the ARIMA model was constructed and it was found that the ARIMA (1, 1, 1) was the model that most excellently fitted the data in question. Furthermore, residual tests were performed to determine whether the residuals of the estimated equation followed a random walk process in the series. The authors found that the ALSI resembles a series that follow random walk hypothesis with strong evidence of a wide variance between forecasted and actual values, indicating little or no forecasting strength in the series. To further validate the findings in this research, the variance ratio test was conducted under heteroscedasticity and resulted in non-rejection of the random walk hypothesis. It was concluded that since the returns follow the random walk hypothesis, it can be said that JSE, in terms of efficiency, is on the weak form level and therefore opportunities of making excess returns based on out-performing the market is ruled out and is merely a game of chance.


Author(s):  
Rozana Liko ◽  
Artion Kashuri ◽  
Miftar Ramosaco

The purpose of this paper is to test whether the Albanian exchange rate market is weak form efficient by studying the statistical behavior of daily Euro and USD exchange rate against Albanian Lekё, which are the most influential currency in Albania market, during the period January 05, 2010 – April 30, 2015. The study seeks to examine whether this currencies follow each a martingale. The unit root tests (individually and panel) and variation ratio test are used. The various analytical tests implemented in the study provide evidence of non-martingale property of exchange market in Albania.


2021 ◽  
Vol 4 (1) ◽  
pp. 62-77
Author(s):  
DA Kuhe ◽  
J Akor

The Random Walk Hypothesis (RWH) states that stock prices move randomly in the stock market without following any regular or particular pattern and as such historical information contained in the past prices of stocks cannot be used to predict current or future stock prices. Hence, stock prices are unpredictable and that investors cannot usurp any available information in the market to manipulate the market and make abnormal profits. This study empirically examines the random walk hypothesis in the Nigerian stock market using the daily quotations of the Nigerian stock exchange from 2nd January, 1998 to 31st December, 2019. The study employs Augmented Dickey-Fuller unit root test, the random walk model, Ljung-Box Q-statistic test for serial dependence, runs test of randomness, and the robust variance ratio test as methods of analyses. The result of the study rejected the null hypotheses of a unit root and random walk in the stock returns. The null hypothesis of no serial correlation in the residuals of stock returns was also rejected indicating the presence of serial correlation/autocorrelation in the residual series. The result of the runs test rejected the null hypothesis of randomness in the Nigerian stock returns. The results of the variance ratio test under homoskedasticity and heteroskedasticity assumptions both strongly rejected the null hypothesis of a random walk for both joint tests and test of individual periods. Based on the results of the four tests applied in this study, it is concluded that the Nigerian daily stock returns under the period of investigation do not follow a random walk and hence the null hypothesis of a random walk is rejected. The results of the study further revealed that the Nigerian stock market is weak-form inefficient indicating that prices in the Nigerian stock market are predictable, dependable, consistently mispriced, inflated, liable to arbitraging and left unprotected to speculations and market manipulations. The study provided some policy recommendations


2002 ◽  
Vol 1 (1) ◽  
Author(s):  
Merlina Widjaja ◽  
Endang Ernawati

Since 1988, Indonesian capital market, especially Jakarta Stock Exchange has been grown fast. Then, come up questions about capital market efficiency. The capital market is efficient if the securities prices reflecting all available informations and the prices are fair. Thus, investor could not achieve abnormal return. So, with this reasons and facts, the research analyze weak form Indonesia capital market efficiency at Jakarta Stock Exchange in periode January-July 2001. This research used samples 25 emitent. Autocorrelation test, run test, and variance ratio test were used to test the capital market efficiency. The result is that Indonesian capital market is efficient in weak form with 1% significance level. It means that securities movement have random walk pattern. Thus, investors could not achieve abnormal return if just used technical analysis with past securities prices data to predict prices in the future.


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