The Efficient Market Hypothesis and the Stock Market Crash A Random Walk With an Occasional Surprise

1988 ◽  
Vol 8 (5) ◽  
pp. 23-26
Author(s):  
Dr Alexandra Hardie
2019 ◽  
Vol 7 (9) ◽  
pp. 134-140
Author(s):  
Mphoeng Mphoeng

The theory of the Efficient Market Hypothesis (EMH) has been debated extensively. In this study the runs test was employed on the Botswana Stock Exchange daily Domestic Companies and Foreign Companies indices to test whether the Botswana stock market follows the random walk process and subsequently determine weak-form market efficiency. The results of the runs test showed that the indices do not follow the random walk process. As a result the Botswana stock market is determined to be weak-form market inefficient and rejects the efficient market hypothesis accordingly.


Author(s):  
Athina Bougioukou

The intention of this research is to investigate the aspect of non-linearity and chaotic behavior of the Cyprus stock market. For this purpose, we use non-linearity and chaos theory. We perform BDS, Hinich-Bispectral tests and compute Lyapunov exponent of the Cyprus General index. The results show that existence of non-linear dependence and chaotic features as the maximum Lyapunov exponent was found to be positive. This study is important because chaos and efficient market hypothesis are mutually exclusive aspects. The efficient market hypothesis which requires returns to be independent and identically distributed (i.i.d.) cannot be accepted.


Pravaha ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 187-198
Author(s):  
Shanker Dhodary

The purpose of this paper is to examine the random walk hypothesis (RWH) by testing the weak-form efficiency in the Nepalese capital market. Descriptive, correlation and causal comparative research design has been used for analyzing the variables and different phenomenon. This research has been prepared only with the help of secondary data. Closing price of company has been collected and analyzed for the period 2015/16-2019/20. Thus researcher tried to analyze the market efficiency with the help of five years data (daily closing price).There are altogether around 233 companies listed in NEPSE. So to make this research feasible and simple researcher has selected only 10 companies from the NEPSE by using purposive sampling technique. In course of selecting company researcher has tried to incorporate only financial sectors as commercial banks, finance companies, insurance, and microfinance companies but development bank has not been taken as sample due to same nature of commercial bank. Researcher examined the weak form efficiency of the Nepal stock exchange (NEPSE) using auto correlation test (parametric test) and run test (non-parametric test) for the period of 2015/16-2019/20. Mainly this research work tested the efficient market hypothesis of Nepalese stock market with the help of daily closing price of 10 Sample Company of different sectors. The market is inefficient in the weak form implies that the NEPSE does not follow a random walk. This means that the NEPSE provides an opportunity for out- performance by skillful managers and investment specialists. Auto correlation exists in price of stock evident that there is high level of dependency of price of stock with the previous ones. It will be easy for speculator and trader to exploit the market and gain handsome profit from the market. All investor are not assumed to be rational in inefficient market, most of the people say investor are investing on the basis of market rumor. Market may be inefficient due the asymmetric of information and insider trading.


Author(s):  
Cristina Vasco ◽  
Pedro Pardal ◽  
Rui Teixeira Dias

This chapter aims to test the hypothesis of an efficient market, in its weak form, in the stock markets of Brazil, China, South Korea, USA, Spain, Italy, in the period from December 2, 2020 to May 12, 2020. The results show that the market efficiency hypothesis is rejected in all markets. In corroboration the DFA exponents show long memories, which put in question the market efficiency, in its weak form, suggesting that the stock markets analyzed show some predictability. In conclusion, investors should avoid investing in stock markets, at least while this pandemic lasts, and invest in less risky markets in order to mitigate risk and improve the efficiency of their portfolios.


2021 ◽  
Vol 13 (2) ◽  
pp. 79-88
Author(s):  
Janesh Sami

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.


2019 ◽  
pp. 107-116
Author(s):  
Jacek Karasiński

The purpose of this article is to examine whether returns of main indexes of selected stock exchanges in the European Union are subject to the random walk model proposed by L. Bacheliere in 1900, which is considered by many researchers to be a synonym of a weak form of the efficient market. The research was conducted for the main indexes of eight selected European stock exchanges representing markets of a different capitalisation. In order to check whether the level of informational efficiency was stable in a whole research period, namely in the years 2000-2017, the research period was divided into three equal six years sub-periods. To test a weak form of the efficient market hypothesis (EMH), four different tests of returns distribution normality were done for daily, weekly, monthly and quarterly intervals. The conducted study allowed for rejecting the null hypothesis saying that returns are subject to the random walk model proposed by L. Bacheliere which leads to normal distribution. Moreover, some significant differences between the research periods occurred. Nonetheless as the random walk model seems to be too strict even for the biggest European markets, it is proposed to test whether the returns can be subject to other stable distributions like the Pareto distribution, which gives higher probability to extremely low and high returns of what resembles actual price fluctuations of financial markets.


2021 ◽  
Vol 4 (3) ◽  
pp. 1-5
Author(s):  
Jiaxuan Xu

The efficient market hypothesis is one of the most important theories in finance. According to this hypothesis, in a stock market with sound laws, good functions, high transparencies, and extensive competitions, all valuable information is timely, accurately, and fully reflected in the trend of stock prices including the current and future values of enterprises. Unless there are market manipulations, it would be impossible for investors to gain more above the average profits in the market by analyzing former prices. Since the efficient market hypothesis has been introduced, it has become an interest in the empirical research of the security market. It is one of the most controversial investment theories and there are many evidences supporting and also opposing this hypothesis. Nevertheless, this hypothesis still holds an important status in the basic framework of mainstream theories in modern financial markets. By analyzing simulated investment transactions in regard to stock trading of three different enterprises, this paper verified that the efficient market hypothesis is partially valid.


This study; Nigerian Stock Exchange and Efficient Market Hypothesis was done using All Share Index (ASI) with daily data from January 02, 2014 to May 20, 2019 (1333 observations) and annual data from 1985 to 2018 (34 observations) collected from the Nigeria Stock Market fact books. The study employed three analytical methods namely the unit root test, GARCH Model and the Autocorrelation cum patial autocorrelation method for the assessment of weak form hypothesis on the daily and annual all share index in the Nigerian Stock market. The results of these evaluations indicated a significant relationship between the price series and their lagged values implying that stock price series do not follow a random walk process in Nigerian stock market. Thus, affirming that the Nigeria Stock Exchange is not efficient in weak form. In the light of this, the researchers recommend that the supervisory and regulatory authorities should strengthen the Nigerian Stock Market through palliating its regulations pertaining to transparency of information management rules such as market barriers and stringent listing requirement, publication of accounts, notices of annual general meeting and the like.


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