Weak-form Efficiency Research Articles

Testing weak form efficiency on the capital markets in Serbia

Testing weak form efficiency on the capital markets in Serbia

Analysis & Test of Market Efficiency: A Case Study of KSE

This study employs more recent and comprehensive data (1997-2013) for the empirical verification of weak form efficiency in Karachi Stock Exchange (KSE). We use Augmented Dickey Fuller (ADF) and Philips-Perron (PP) tests to detect unit root in the daily returns series. Further, we run Random Walk Model (RWM) to detect unit root in returns series. We use Runs test to detect any possible serial correlation in residuals. Results are in support of weak form efficiency. However, the study argues that strong form efficiency does not exist in KSE. We compare equity funds returns with KSE 100 Index returns for 10 years (2003-2012) and we find that the mean returns and standard deviations are not much different. However, the correlation between the returns is found to be low which indicates that equity funds do not mimic market index and have very concentrated portfolios comprising of growth stocks. Finally, we also compare the returns and Sharpe ratio for Islamic and conventional equity mutual funds. Since Islamic funds due to investment and trading restrictions can not exactly mimic market portfolio, the return comparison could help in studying whether the contention of EMH proponents that expert investors too can do as good as earning returns on market portfolio is entirely valid or are there some qualifications and exceptions. We report evidence that challenges the EMH proposition.

An Analysis of Weak-Form Efficiency in Banking Sector: A Study with a Special Reference to National Stock Exchange

An Analysis of Weak-Form Efficiency in Banking Sector: A Study with a Special Reference to National Stock Exchange

Testing Weak-Form Market Efficiency of Dhaka Stock Exchange

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

Has the 2008 financial crisis affected stock market efficiency? The case of Eurozone

In this paper, the impact of the 2008 financial crisis on the weak-form efficiency of twelve Eurozone stock markets is investigated empirically. Efficiency is tested via the Generalized Hurst Exponent method, while dynamic Hurst exponents are estimated by means of the rolling window technique. To account for biases associated with the finite sample size and the leptokurtosis of the financial data, the statistical significance of the Hurst exponent estimates is assessed through a series of Monte-Carlo simulations drawn from the class of α-stable distributions. According to our results, the 2008 crisis has adversely affected stock price efficiency in most of the Eurozone capital markets, leading to the emergence of significant mean-reverting patterns in stock price movements.

The efficiency of the stock market in Serbia

The paper analyzes the application of the hypothesis of the efficiency of financial markets on the financial market in Serbia, i.e. the Belgrade Stock Exchange. The weak form presupposes an impossibility of anticipating a future share price on the basis of available historical pieces of information about the prices, indicating a “random walk” trend with shares. In order to carry out a research into the weak form of efficiency, the BELEX15 Index return daily value of the most liquid shares on the Belgrade Stock Exchange from the beginning of 2006 to the end of 2013 is taken. In order to prove the (un)predictability of the share-price trend, time series stationarity is established by means of the parametric and non-parametric econometric tests, such as the Dickey–Fuller test, the Phillips–Peron (PP) test and the Run Test.

Bidding structure, market efficiency and persistence in a multi-time tariff setting

The purpose of this study is to examine the fractal dynamics of day ahead electricity prices by using parametric and semi parametric approaches for each time zone in a multi-time tariff setting in the framework of bidding strategies, market efficiency and persistence of exogenous shocks. We find that that electricity prices have long term correlation structure for the first and third time zones indicating that market participants bid hyperbolically and not at their marginal costs, market is not weak form efficient at these hours and exogenous shocks to change the mean level of prices will have permanent effect and be effective. On the other hand, for the second time zone we find that price series does not exhibit long term memory. This finding suggests the weak form efficiency of the market in these hours and that market participants bid at their marginal costs. Furthermore this indicates that exogenous shocks will have temporary effect on electricity prices in these hours. These findings constitute an important foundation for policy makers and market participants to develop appropriate electricity price forecasting tools, market monitoring indexes and to conduct ex-ante impact assessment.

Sculpture Market Efficiency and the Impact of Auction House Art Experts

In this study I examine the absolute and time-varying weak-form market efficiency of the international sculpture auction market. The results indicate that the sculpture market efficiency varies ove ...

Malaysian finance sector weak-form efficiency: Heterogeneity, structural breaks, and cross-sectional dependence

This study examines the weak-form efficient market hypothesis (EMH) for the Finance Sector in Malaysian Stock Exchange, by exploring and scrutinizing the firm-level efficiency over for the period from 1st January 1997 to 31st December 2014. For this purpose, we apply panel nonlinear unit root test that accounts for heterogeneity, and panel stationarity test to allow for the presence of structural breaks and cross-sectional dependence (CSD). The main findings of this study suggest the following: first, there is a strong CSD among the price series of finance stocks; second, unlike the traditional panel unit root tests that provide mixed-results, the panel stationarity test which incorporates structural breaks and CSD suggests that these series are characterized as random walk processes implying the Finance Sector is weak-form efficient. The finding of weak-form efficiency has salient implications in terms of capital allocation, stock price predictability, forecasting technique, and the impact of shocks to stock prices.

Random Walk Investigation in Indian Market with special reference to S&P Nifty – Fifty Stocks

The competence of a financial system is entirely depending upon the stock market efficiency. The gradual growth of equity investor’s participation is inevitable to enrich the overall growth of emerging economies.Hence the necessity is felt to provide an empirical support to the investing community. For the purpose, this study attempts to examine the weak-form efficiency of Indian stock market – National Stock Exchange (NSE). The study has used the daily closing price of the Nifty fifty stocks from 3rdJanuary 2011 to 24thApril 2015. To test the weak form efficiency both parametric and non-parametric tests called Autocorrelation, Augmented Dicky Fuller test, and Runs Test were performed. The study reveals that 39 stocks of NSE-Nifty Fifty are found to be weak form inefficient, so that the investors can formulate trading strategies to gain abnormal returns. The Index and 10 stocks are found to be weak form efficient during the study period since the price series found to be autocorrelation existence.

Predictability of Implied Volatility: Evidence from the Over-the-counter Currency Option Markets

This paper provides an empirical study on the predictability of implied volatility using dataset collected from the London over-the-counter currency option market. The present work is motivated by the lack of empirical studies that address implied volatility characteristics across various maturities. We applied both in and out-of-sample tests that include the nonparametric variance ratio and interval forecasts methodologies. Contrary to the weak-form market efficiency theory, this study provides evidence of non-random movement in the implied volatility series and indicates predictability of implied volatility series. The result suggests that there is a need to account for the differences in data characteristics that exist across the volatility term structure.

Investigating stock market efficiency: A look at OIC member countries

The tremendous growth of emerging and developing markets bring forth new arenas of research. One such area is the efficiency of stock markets. In light of the Efficient Market Hypothesis (EMH) several studies have been undertaken over the past two decade, with much focus being on developed markets and certain developing countries. However, a dearth in literature is seen for this niche on Organization of Islamic Conference (OIC) member countries. Following the recent global crisis, attention on emerging and developing markets have increased tremendously, questioning whether these countries’ market are apt in withstanding influxes of capital without crashing. The OIC despite its global presence and potential has often been criticized about its stock markets, which are marred by underdevelopment and illiquidity. This paper focuses on analysing the weak-form efficiency of OIC member stock markets to determine their efficiency rankings during different business cycles. Our results are indicative of improving efficiency over the past decade.

Stock market efficiency and liquidity: The Indonesia Stock Exchange merger

This study investigates the market liquidity and efficiency of the merger between the Surabaya Stock Exchange and the Jakarta Stock Exchange into the Indonesia Stock Exchange (IDX). Efficiency theory and scale economies are applied to identify the liquidity and efficiency levels of firms. Results indicate that large market capitalization companies and the non-financial sector achieved greater market efficiency than their counterparts. Despite foreign ownership reduces market efficiency for large market capitalization firms, small market capitalization firms increase market efficiency via merger. The IDX composite index demonstrated weak-form efficiency, with LQ45 index returns explaining up to 29.3% of the price movements and up to 8.5% of the IDX returns.

The Pre-Holiday Effect in China: Abnormal Returns or Compensation for Risk?

This study examines the pre-holiday effect in the Chinese stock market. It provides new insights into the weak-form efficiency of China's equity market indexes. Using the GARCH (1,1) model, we find the pre-holiday effect in broad-based Chinese stock returns and in size, value and growth style indexes. Further analysis using a GARCH (1,1)-M model suggests that the pre-holiday effect at both market and industry/sector levels can be attributed to time-varying risk. We show the pre-holiday effect reflects abnormal returns in small-cap, large-cap and growth style indexes while this same effect reflects compensation for bearing risk in value stocks.

Weak-Form Efficiency of the U.S. Dollar (USD) and Korean Won (KRW) Currency Market

Weak-Form Efficiency of the U.S. Dollar (USD) and Korean Won (KRW) Currency Market

Testing weak form efficiency in the South African market

This paper furthers the work on efficiency of developing markets with specific focus on the JSE Limited. Empirical work on the efficiency of the JSE has been mixed; evidence both in favour of and against weak form efficiency is prominent. If markets are efficient new information immediately influences market prices; accordingly, prices follow a random walk and investors will not be able to continuously earn abnormal returns. Both the Augmented Dickey-Fuller and Phillips-Perron tests were employed to test whether the JSE followed a random walk between 1999 and 2014. The null hypothesis (H0) for both tests is that the series of logarithmic returns has a unit root and is therefore weak form efficient. In both tests this H0 is rejected, which proves that for the period under analysis the JSE was not weak form efficient. The influence of factors such as market size and liquidity on efficiency is also discussed.

Is Pharmaceuticals Industry Efficient? Evidence from Dhaka Stock Exchange

This study examines the weak form market efficiency of the thirteen listed pharmaceuticals company of Dhaka Stock Exchange (DSE). We exclude the three listed pharmaceuticals company because of their newly enlistment at DSE. The data consists of the daily returns from 1 st January, 2009 to 31 st December, 2013. The returns of all pharmaceuticals companies are not normally distributed. Unit root test, serial correlation test and runs tests are being used for testing weak form efficiency of the individual stocks return. The findings of the runs test is completely rejecting the random walk theory for all thirteen securities whereas the augmented dickey-fuller (ADF) test are showing inverse result with its all three equations suggesting the weak form efficiency of the Pharmaceuticals stock return. The results of the Autocorrelation and Box-Ljung statistics support random walk theory for ten companies and reject it for ACI, Reckitt Benckiser and Pharma Aid. However, from the summery of findings we can agree that the Pharmaceuticals industry of Bangladesh is just becoming weak-form efficient.

Random Walks in Daily Foreign Exchange Rates? The Case of Lebanon (2010-2015)

In most of the academic literature on asset prices, like equities or foreign exchange, the words weak-form efficiency and random walk are used interchangeably. This paper makes a distinction between these two concepts. Weak-form efficiency holds when price increments are independent and random. A random walk is more stringent: it requires that the probability distribution of price increments be identical and normal, in addition of being independent. As expected the null hypothesis of a random walk is rejected with force while the null of weak-form efficiency is not. This implies that linear filter rules, chartism, and technical analysis cannot produce abnormal profits. But this implies also that non-linear filter rules, chartism, and technical analysis can be profitable. This explains the reality of finding departments of technical analysis in most Lebanese banks. If the market experience of Lebanon is generalized to other countries this would explain why international banks also have such departments.

Testing the weak-form efficiency of stock markets

Purpose – The purpose of this paper is to focus on the weak-form efficiency of 24 emerging and nine industrial stock market indices around the world. It tests for the predictability and the presence of seasonal patterns in rates of return from January 2000 to December 2010. Design/methodology/approach – It reports on the descriptive statistics for estimated monthly percentage returns. This is complemented by the use of both parametric and non-parametric techniques to test for abnormal return behaviour in stock markets. Findings – The results show that: first, emerging economies which persisted with market-oriented reforms had higher returns relative to risk, indicating their attractiveness for risk diversification; second, successive changes in stock prices were interrelated with each other and therefore contained information for predicting future prices in two-thirds of the emerging markets compared to one-third of industrial economies; and third, the turn-of-the calendar year effect was present for half of the emerging markets vis-à-vis one-quarter of the developed countries. The authors found limited support for the tax-loss selling hypothesis for both the emerging and industrial economies. Research limitations/implications – The paper fails to specifically analyse the implications for security returns of changes in technology, institutions, volume of trading and regulations in the different stock markets. Practical implications – The results should be particularly informative for foreign investors with regard to the risk diversification benefits of the various emerging and industrialised stock markets and the expected risk-return trade-offs. Originality/value – The paper provides a more powerful explanation for the role of institutional arrangements, infrastructure, culture and other country-specific risk factors in asset pricing compared to disparate case studies.

Does the Indian Stock Market Exhibit Random Walk?

The efficient market hypothesis (EMH) states that security prices reflect all available information and investors cannot earn excess return by trading on the basis of this information. EMH is an important concept for the stockbrokers, financial institutions, individual and institutional investors and regulators government. An investment strategy of an investor is greatly influenced by market efficiency. Market efficiency also dictates the regulatory measures to be developed for ensuring the orderly development and management of the markets in a country. This study intends to contribute to the existing literature by investigating the weak-form market efficiency. The efficiency of the Indian stock market is tested by using the daily data of Bombay Stock Exchange (BSE)-200 index-based companies over the period of 1 January 1991 to 31 December 2012 by employing runs test, augmented Dickey–Fuller test (ADF) Test, Phillips–Perron test (PP) test, autocorrelation test and generalized autoregressive conditional heteroscedasticity (GARCH) (1, 1) model. The empirical results of these tests do not support the weak-form efficiency for the Indian stock market. Therefore, we conclude that the Indian stock market is not weak-form efficient. This result suggests that there is a systematic way to exploit the trading opportunities in the Indian stock market and the investors can earn abnormal profits by exploiting this opportunity. Since the results indicate that the market is not efficient in the weak form, the study of historical prices is beneficial for the investors. This also means that there is a scope for technical analysis as a trading strategy. The findings also open up scope for the market regulators to initiate measures to ensure market efficiency. There is an overwhelming literature supporting the weak-form market efficiency. We employ multiple tests to investigate the dependence structure of the historical prices to unravel the myth of market efficiency in the weak form.