Empirical Challenges of the Efficient Market Hypothesis

Capital markets provide a function which facilitates the buying and selling of long-term financial securities to increase liquidity and their value, Watson & Head (2013). Hence, the Efficient Market Hypothesis (EMH) explains the relationship that exists with the prices of the capital market securities, where no individual can beat the market by regularly buying securities at a lower price than it should be. This means that in order to be an efficient market prices of securities will have to fairly and fully reflect all available information, Fama (1970). Consequently, Watson & Head (2013) believe that market efficiency refers to the speed and quality of how share price adjusts to new information. Nevertheless, the testing of the efficient markets has led to the recognition of three different forms of efficiency in which explains how information available is used within the market. In this essay, the EMH will be analysed; testing of EMH will show that the model does provide strong evidence to explain share behaviour but also anomalies will be discussed that refutes the EMH. Therefore, a judgment will be made to see which structure explains the efficient market and whether there are some implications with the EMH, as a whole.

It is believed that Efficient Market Theory is based upon some fallacies and it does not provide strong grounds of whatever that it proposes. More importantly the Efficient Market theory is perceived to be too subjective in its definition and details and because of this it is close to impossible to accommodate this theory into a meaningful and explicit financial model that can actually assist investors in making the investment decisions (Andresso-O’Callaghan, B., 2007).

As Chapter 10 questions, if further evidence continues to surface that capital markets do not always behave in accordance with the efficient market hypothesis, then should we reject the research that has embraced the EMH as a fundamental assumption? In this regard we can return to earlier chapters of this book in which we emphasised that theories are abstractions of reality. Capital markets are made of individuals and as such it would not (or perhaps, should not) be surprising to find that the

The Efficient-Market Hypothesis (EMH) states that it is impossible to beat the market because stock market efficiency causes existing share prices to always incorporate and reflect all relevant information.

It was previously assumed that economic investors and regulators (agents) utilised all available information and thus market prices were a reflection of this information with assets representing their fundamental value, encouraging the position that agents’ actions were rational. The 2007-2008 Global Financial Crisis (GFC) is posited to have originated from the notion that all available information was utilised, causing agents to fail to thoroughly investigate and confirm “the true values of publicly traded securities,” leading to a failure to register the presence of an asset price bubble preceding the GFC (Ball 2009).

Loss aversion is the tendency for people to fear loss. The authors explain that this fear of loss can lead to unpredictable and often ruinous actions. It is shown that as the potential for loss increases, the stronger this force becomes. For example, many individuals encounter loss aversion when buying and selling stocks. During the Great Recession in the late 2000s, many stockholders experienced their stocks drastically drop in value. They feared if they sold their stocks, it would result in a tremendous loss of money. This fear of loss influenced many stockholders to hold on to their stocks hoping for them to rise back to their original value. Many stocks never increased in value after this incident. As a result, countless stockholders lost an immense amount of money. Loss aversion is an extremely strong force, however, it can be minimized by focusing on the big picture rather than short term consequences. If these stockholders had looked at the big picture and focused on studying the true value of each stock, they would have been able to minimize the amount of loss they would have to suffer.

The premise of an efficient market is that stock prices adjust accordingly as information is received. The speed and accuracy of the pricing changes are a reflection of the strength of the market efficiency, where in theory a perfectly efficient market will re-adjust prices immediately and precisely with new information. The efficient market hypothesis aligns with beliefs about whether technical and fundamental analyses are useful in making investment decisions or whether a passive approach is appropriate. In a perfectly efficient market, these types of analyses are not able to predict stock price trends (based on market inefficiencies or price abnormalities) which could assist in portfolio positioning or investment management. However, some investors belive that the market pricing is not precise and that there are timing windows and pricing trends that can be identified through analysis of past performance and finding price abnormalities where all information is not correctly reflected in the stock price (Hirt, Block and Basu, 2006).

sider BACKGROUND Efficient market theory examines how accurately stock prices signal resource allocation alloc and fully reflect all available information. Fama (1970) introduced the efficient market hypothesis stating there are three forms of efficiency: weak, semi strong, and strong. A market semi-strong, that incorporates all historical information is said to be weak form efficient, while one that responds to all publicly available informatio is semi-strong efficient. In a semiinformation -strong efficient market, prices instantly change to reflect publicly available information. A strong form market, strong responds to all information, both public and private. The hypothesis claims that achieving above average returns on a risk adjusted basis is impossible (Fama 1970). (Fama, The lowest level of market efficiency, weak form, states that the market only reacts to historical information. This means that no one can earn above normal returns based on published historical information; however, the market does not quickly react to new public or private information. It may be possible then, in a weak form efficient market, to obtain abnormal returns form using either new publicly available or private insider information (Fama 1970). (Fama, A semi-strong form market is more efficient that a weak form, as it reacts to publicly strong available new information quickly and share prices adjust to reflect the market’s reaction. share Obtaining

The efficient-market hypothesis (EMH) is one of the well-known methods for measuring the future value of stock prices. According to this hypothesis, the market is efficient if its prices are formed on the basis of all disposable information. According to EMH if there is a possibility to predict the future price of shares, that is the first sign of an inefficient market.

An efficient market is one in which share prices quickly and fully reflect all available information, where investors are rational, and there are no frictions. Investors determine stock prices on the basis of expected cash flows to be received from a stock and the risk involved. Rational investors should use all the information they have available or can reasonably obtain, including both known information and beliefs about the future. In an efficient market there is “no free lunch”: no investment strategy can earn excess risk-adjusted average returns, or average returns greater than are warranted for its risk (Barberis, 2003). Market efficiency is assessed by determining how well

Efficient Market Hypothesis has been controversial issues among researcher for decades. Until now, there is no united conclusion whether capital markets are efficiency or not. In 1960s, Fama (1970) believed that market is very efficient despite there are some trivial contradicted tests. Until recently, both empirical and theatrical efficient market hypothesis was being disputed by behavior finance economist. They have found that investor have psychological biases and found evidences that some stocks outperform other stocks. Moreover, there are evidences prove that market are not efficient for instance financial crisis, stock market bubble, and some investor can earn abnormal return which happening regularly in stock markets all over the world. Therefore, the purpose of this essay is to demonstrate that Efficient Market Hypothesis in stock (capital) markets does not exist in the real world by proofing four outstanding unrealistic conditions that make market efficient: information is widely available and cost-free, investor are rational, independent and unbiased, There is no liquidity problem in stock market, and finally stock prices has no pattern.

The efficient market, as one of the pillars of neoclassical finance, asserts that financial markets are efficient on information. The efficient market hypothesis suggests that there is no trading system based on currently available information that could be expected to generate excess risk-adjusted returns consistently as this information is already reflected in current prices. However, EMH has been the most controversial subject of research in the fields of financial economics during the last 40 years. “Behavioural finance, however, is now seriously challenging this premise by arguing that people are clearly not rational” (Ross, (2002)). Behavioral finance uses facts from psychology and other human sciences in order to

The analysis of this paper will derive the validity of the Fama and French (FF) model and the efficiency of the Capital Asset Pricing Model (CAPM). The comparison of the Fama and French Model and CAPM (Sharpe, 1964 & Lintner, 1965) uses real time data of stock market to practise its efficacy. The implication of the function in realistic conditions would justify the utility of the CAPM theory. The theory suggests that the expected return demanded by investors on a risky asset depends on the risk-free rate of interest, the expected return on the market portfolio, the variance of the return on the market portfolio, and

First time this phenomenon was presented by the economists Rajnish Mehra and Edward Prescott in 1985. They discovered that the return from US equity investments in comparison to the return from a risk free government securities had been much far above during the twentieth century to be interpreted by the traditional economic theories (Siegel and Thaler, 1997).

Richard Roll, and University and Auburn, University of Washington, and University of Chicago educated economist, began his career researching the effect of major events of stock prices. This experience likely helped him reach the two conclusions he makes in his 1977 “A Critique Of The Asset Pricing Theory’s Tests”, one of the earliest and most influential arguments against CAPM. In the paper, Roll makes two major claims: that CAPM is actually a redundant equation that just further proves the concept of mean-variance efficiency, and that it is impossible to conclusively prove CAPM. His first claim relates to mean-variance efficiency: the idea that mathematically one must be able to create a portfolio that offers the most return for a given amount of risk. Roll claims that all CAPM is doing is testing a portfolio’s mean variance efficiency, and not actually modeling out projected future returns. The second claim in the paper is that there is not enough data about market returns for CAPM to ever prove conclusive. Even if modern technologies could help alleviate some of the burden of testing market returns for publicly traded equities, there is still no way to account for the returns of less liquid markets, where there is less public information. This means it is impossible for