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This paper examines the Random Walk Hypothesis (RWH) for aggregate New Zealand share market returns, as well as the CRSP NYSE‐AMEX (USA) index during the 1980‐2001 period. Using several indices, we rely on the variance‐ratio test and find evidence to support the rejection of the RWH with some evidence of a momentum effect. However, we find evidence to suggest the behaviour of share prices to be time‐dependent in New Zealand. For example, we find the indices tested were closer to random after the 1987 share market crash. Further analysis showed even stronger results for periods subsequent to the passage of the Companies Act 1993 and the Financial Reporting Act 1993. We also find evidence that indices based on large capitalisation stocks are more likely to follow a random walk compared to those based on smaller stocks. For the USA index, we find stronger evidence of random behaviour in our sample period compared to the earlier period examined by Lo and Mackinlay (1988)

This study seeks to measure the behaviour of stock prices in the Bahrain Stock Exchange (BSE), which is expected to follow a random walk. The aim of the study is to measure the weak‐form efficiency.

Random walk models such as unit root and Dickey‐Fuller tests are used as basic stochastic tests for a non‐stationarity of the daily prices for all the listed companies in the BSE. In addition, autoregressive integrated moving average (ARIMA) and exponential smoothing methods are also used. Cross‐sectional‐time‐series is used for the 40 listed companies over the period 1 June 1990 up until 31 December 2000.

Random walk with no drift and trend is confirmed for all daily stock prices and each individual sector. Other tests, such as ARIMA (AR1), autocorrelation tests and exponential smoothing tests also supported the efficiency of the BSE in the weak‐form.

The finding of the study is a necessary piece of information for all investors whether in Bahrain or dealing with Bahrain stock market. Listed firms could also benefit from the findings by seeing the true picture of their stock price. Since, Bahrain is considered as an emerging market, the new methodologies used could be replicated for all other emerging markets. In addition, the finding is used as a base for testing the market efficiency in the semi‐strong form, which has not yet been tested by any researcher.

This study will add value to the literature of market efficiency in emerging market since it is the only study which covers all the listed companies and over a long period of time. To confirm the weak‐form efficiency in Bahrain, the study is unique in using five different methods in the same paper which have not been found in the previous literature.

The existence of weak‐form efficiency in the equity markets of the three main Central European transition economies (the Czech Republic, Hungary, and Poland) is examined for the period July 1995 through September 2000, using weekly Investable and Comprehensive indexes developed by the International Finance Corporation. Several different approaches are used. Univariate and multivariate tests provide some evidence that stock prices in these exchanges exhibit a random walk, which constitutes evidence for weakform efficiency. This differs in some cases from studies using data for the initial years of these markets. The variance ratio test (VR) of Lo and MacKinlay (1988) yields somewhat mixed results concerning the random‐walk properties of the indexes. A modelcomparison test compares forecasts from a NAÏVE model with ARIMA and GARCH alternatives. Results from the model‐comparison approach are consistent in rejecting the random‐walk hypothesis for the three Central European equity markets.

This paper investigates whether stock‐price indexes of emerging markets can be characterized as random walk (unit root) or mean reversion processes. We implement a panelbased test that exploits cross‐sectional information from seventeen emerging equity markets during the period January 1985 to April 2002. The gain in power allows us to reject the null hypothesis of random walk in favor of mean reversion at the 5 percent significance level. We find a positive speed of reversion with a half‐life of about 30 months. These results are similar to those documented for developed markets. Our findings provide an interesting comparison to existing studies on more matured markets and reduce the likelihood of earlier mean reversion findings as attributable to data mining.

Recent research indicates that the random walk hypothesis (RWH) approximately describes the behavior of major dollar exchange rates during the post‐1973 float. The present analysis seeks to examine the profitability of currency futures trading rules that assume that spot exchange rates can be adequately modeled as a driftless random walk.

Two random walk currency futures trading rules are simulated over all available data from the period 1984‐2003. In both cases, the investor buys currencies selling at a discount and sells those selling at a premium, as the RWH implies. The two rules differ only in the way they allocate the hypothetical investor's resources among long and short foreign currency positions.

Results show that an investor who used these trading strategies over the past decade would have enjoyed large cumulative gains, although periods of profit were interrupted by periods of substantial loss.

The findings encourage the hope that profitable random‐walk‐based strategies for currency futures trading can be devised. The simulation results have important implications for those willing to hedge, borrowers, and speculators.

This paper provides evidence that purchasing futures contracts on currencies priced at a discount and selling futures contracts priced at a premium has generally been a profitable trading strategy during the last two decades of floating exchange rates.

This paper aims to study the weak form of efficiency of Indian capital market during the period of global financial crisis in the form of random walk.

The study considered daily closing prices of S&P CNX Nifty, BSE, CNX100, S&P CNX 500 from April 1, 2005 to March 31, 2010. The data source is the equity market segment of NSE and BSE. Both parametric and nonparametric tests (“ex‐posts” in nature) are applied for the purpose of testing weak‐form efficiency. The parametric tests include Augmented Dickey‐Fuller (ADF) unit root tests and nonparametric tests include Phillips‐Perron (PP) unit root tests and Run test. ADF tests use a parametric autoregressive structure to capture serial correlation and PP tests use non‐parametric corrections based on estimates of the long‐run variance of ΔY_t.

The results suggested that the Indian stock market was efficient in its weak form during the period of recession. It means that investors should not be able to consistently earn abnormal gains by analysing the historical prices. Hence one should not be able to make a profit from using something that everybody else knows.

The study reports that all the stocks in these selected indices are fundamentally strong and their prices are not influenced largely by historical prices and other relevant factors which came from industry and any other information that is publically available. Thus it can be concluded that the Indian stock market was informationally efficient and no investor can usurp any privileged information to make abnormal profits.

Where past studies have examined the weak‐form of efficiency of various markets and the effect of globalisation and global financial crisis on the various sectors of developing and emerging economies, this paper attempts to study the weak form of efficiency of the Indian capital market in the period of recession in the form of random walk.

After adjusting for thin trading, this study seeks to examine the market efficiency for six emerging stock markets in the Gulf Cooperation Council (GCC) countries: Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates.

This study uses the LOMAC single variance ratio (VR) test and the Wright's rank and sign VR tests to examine informational efficiency after correcting the data for thin trading that typically characterizes these indexes.

As the observed indexes in thinly traded markets may not represent the true underlying index value, there is a systematic bias toward rejecting the efficient market hypothesis. The results of this study show that after removing the effect of infrequent trading the random walk hypothesis was not rejected in all GCC equity markets.

To the best of the author's knowledge this is the first study that applies the Wright's rank and sign VR tests after adjusting for thin trading in GCC equity market.

Outlines research on the factors which reduce stock market efficiency and the particular characteristics of the Athens stock exchange (Greece). Uses 1988‐1994 Greek monthly returns data for share actively traded during the period to test for random walk behaviour in share prices. Explains the methodology, which is based on Lo and Mckinlay’s (1988) variance ratio test procedure and Robinson’s (1991) test for fractional integration; and presents the results which support the random walk hypothesis, i.e. suggest weak‐form efficiency. Notes inconsistency with some previous research on the Athens stock exchange and other emerging stock markets, but consistent with the idea that recent institutional changes have succeeded in increasing efficiency.

The purpose of this paper is to examine volatility and the weak-form efficient market hypothesis (random walk) of world spot crude oil market.

The study uses the generalized autoregressive conditional heteroskedasticity (GARCH-M), exponential generalized autoregressive conditional heteroskedasticity (EGARCH), and threshold GARCH (TGARCH) models. The data are selected from three markets: Dubai Vetch (DV), West Texas Intermediate, and Europe Brent Spot Price.

The weak-form efficient market (random walk) hypothesis was rejected for all estimated GARCH-M, EGARCH, and TGARCH models, indicating that these markets are inefficient and predictable. For daily data, the empirical results showed the presence of asymmetric effects, and the conditional variance process was found to be highly persistent.

This study is unique in its nature as it examines three markets on three continents. In addition, one of these markets (DV) was not carried out by the previous study. This work takes into account the market location.

The purpose of this paper is to re-examine the weak form efficiency of five African stock markets (South Africa, Nigeria, Egypt, Ghana and Mauritius) using various tests to assess the impact of non-linearity effect and thin trading which are prevalent in African markets on market efficiency.

The weekly returns of S&P/IFC return indices for five African countries over the period 2000-2013 were obtained from DataStream and analyzed. The study adopted the newly developed Non-Linear Fourier unit root test advanced by Enders and Lee (2004, 2009) which allows for an unknown number of structural breaks with unknown functional forms and non-linearity in data generating process of stock prices series to test the Random Walk Hypothesis (RWH) for the five markets, and an augment regression model.

In light of the empirical evidence the author(s) using Non-linear Fourier Unit Root Test only fail to reject the RWH for South Africa, Nigeria and Egypt leading to the conclusion that these markets follow the RWH and weak-form efficient whilst Ghana and Mauritius are weak-form inefficient. Besides, evaluating non-linear models without adjusting for thin trading effect shows that, South Africa and Ghana markets are weak-form efficient while Nigeria, Egypt and Mauritius are not. However, after accounting for thin trading effect, the author(s) find that South Africa and Egypt markets follow the RWH. The findings imply that market efficiency results depend on the methodology used.

This paper provides further evidence on stock market efficiency in emerging markets. The finding suggests that thin trading and non-linearity effect influences markets efficiency tests in African stock markets. Thus, recent structural adjustment and liberalization policies have not enhanced stock market operations in Africa. This paper therefore has implications for policy makers and international investors.