Validity of the Strong Form of the Efficient Market Hypothesis

2206 words (9 pages) Business Assignment

12th Jun 2020 Business Assignment Reference this

Tags: Business AssignmentsFinanceMarket Analysis

Disclaimer: This work has been submitted by a student. This is not an example of the work produced by our Business Assignment Writing Service. You can view samples of our professional work here.

Any opinions, findings, conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of

Arthur Jensen, a professor at Harvard claimed that “there is no other proposition in economics which has more solid empirical evidence supporting it than the Efficient Market Hypothesis” (Guerrien, B. and Gun, 2011).What is Efficient Market Hypothesis? A paper published in 1970 by Eugene Fama is supposed to explain the definition of Efficient Market Hypothesis (EMH), however it does not. This leaves the ‘hypothesis’ open to different interpetations which caused a lot of confusion. In general, Market Efficiency is a model that would allow us to predict future stock price movements. It is a speculation hypothesis which holds that speculators, who purchase securities at productive costs are given with the proper data and ought to get a rate of return that incorporates the expected chance of the security. Fama’s definition of the theory was:“ an efficient market prices fully reflect available information” (Fama, E.F., 1960).This is not a straightforward definition but we can easily assume that he was trying to say that in order to predict prices we have to look at the information that is available to us. There are three types of Efficiency Forms: Weak form EMH, Semistrong form EMH and finally Strong form EMH. The weak form market efficiency conveys   that it is unimaginable to defeat the market by utilizing verifiable cost and volume information. This negates with the specialized examination which is based on the suspicion that the history rehashes itself and so there must be a few sorts of repetitive cost design. The semistrong frame proficiency is split into three categories: event studies, cross secional predictability of returns and the calendar effect. I will not be going into detail of each category as this essay is going to focus on the strong form of the Efficient Market Hypothersis.The strong form of EMH debate that stock costs completely reflect all accessible data, both open and private. There ought to be no gathering of investors that can reliably beat the market. I will be examining the execution of the following  financial specialist classes: Corporate Insiders, Security Investigators and at last the Proficient Portfolio Managers.

The strong form of Efficient Market Hypothesis is one of the foremost controversial forms of EMH, typically since it is accepted to be exceedingly unreasonable as this form suggests that in case the market is emphatically proficient, you may not be able to utilize chronicled data to anticipate future costs,  you will no longer be able to use publicly available information as well, to predict the furutre. (Kuepper, 2019). It also states that insiders, or other parties that may have some sort of information that may help them to predict future prices that is not available to the public would not be able to use that information. This model is deemed as unrealistic because it is not realistic to say that insiders do not have information that the public does not have, and that they can not exploit the information they have to try to compte with others.

Insiders are regularly characterized as, officers, best official and considerable shareholders. Most of their exchanging falls inside legitimate limits, as it were the abuse of material, nonpublic data is prohibited. At whatever point insiders exchange in offers of their possess company they are committed to record a report with the Securities and Trade Commission. Insider exchanging might have a positive part by making the market more agent and by empowering firms to remunerate their directors for their fruitful entreneurship (Manne, 1966), past studies have highlighted that educated insider exchanging permits insiders to misuse their data advantage over other showcase members and as illustrated permits them to prize out private benefits.

Because of this, policy makers have placed many restrictions on insider trading in order to regulate it, for example: the Security Exchange Act of 1934, the Insider Trading and Securities Fraud Enforcement Act (ITSFEA) and the Stock Enforcement Remedies and Penny Stock Reform Ack ( SERPSRA). There are many reasons why well governed firms are adviced to discourage their insiders from exploiting private information. Firstly by allowing managers to engage in insider trading for their selfish benefits at the expense of shareholders and if corporate governance systems are designed to align the interests of shareholders to those of the managers, these systems should limit managerial rewards and the ability to profit from such trading effectively.  Due to the ITSFEA, firms are responsible for employees’ illegal transactions.

Powerless corporate administration is related with more securities extortion course activities by the Security and Exchane Commission. Consequentently this infers that firms have a solid motivation to embrace well working corporate administration component that can diminish legitimate hazard emerging from educated insider exchanges. Deals exchanges tend to be less instructive than buy exchanges since insiders have numerous reasons to offer their shares that are not related to private information( Helland and Sykuta, 2005).

Studies propose that firms don’t encounter negative irregular return taking after insider’s deal exchanges in later periods, on the other hand insiders proceed to win anomalous benefits from their buy exchanges. This demonstrates that shareholders’ concerns are not high in insider deals but are higher in insider buys, constraining the part of administration components in confining insider deals. There are reasons why great corporate administration demoralises insiders from misusing negative private data. Thinks about appear that insiders abuse private negative data by offering their shares some time before the divulgence of such data which leads them to gain irregular profits (Muller, Neamtiu and Riedl, 2010).

According to Chang and Lo, legal risk related with insider sales are more prominent r than legal risks associated with purchases, such risks are higher if they happen to occur before the release of negative profit news with no warnig about earning disappointments (Chang and Lo,2006)

Seyhun (2000) conducted research on all detailed insider exchanging in all publicly held United States companies over a period of 21 years ( over one million transactions).

He found that large shareholders were able to get a return of 0.7% greater than what the model suggests, which is not much. Directorn managed to get a return of 3.6% greater than what the model suggested, officers managed to get a return of 3.9% while the top executive beat this module by 5%.  This is strong evidence against the strong form of Efficient Market Hypothesis because it simply implies that insiders are still able to beat others and beat the module using legal trading. Return remain consistently greater than the model’s. Insiders’ manage to exploit their information to their advantage, this goes against the strong form of EMH.

This brings me to the second investor class which is security analysts. They are not insiders, however they are professional analysts that are hired, they have the resources to find information that the average investor would not have or find.  This may allow them to predict the future of prices, therefore get a return greater than the model. Brokerage frms spend a lot of money every year analysing stocks in order to give reliable investment advice to cliets. Analysts are not insiders, therefore typically do not have insider informaion but devote a reat deal of evergy studying it. Sell side analyst issue recommentadions as important as whether to buy, sell or hold various stock . Analysts are made to be manipulative and not sincere, recommending stock not because they expect them to perform well, but becausr doing so will increase the investment banking and trading profits of their firms and their own personal investment. They have been criticised by investrors, politicians and regulators in 2001-2 for their power in influencing investrors’ decisions and stock prices. Womack (1996) discovered that the release of suggestions for selling and buying has a significant effect on inventory prices instantly and in the months to come. Stickel (1995) discovered comparable outcomes to Womack in that the abnormal returns following suggestions for buying and selling are in the direction expected.

Last but not least the third investor class which is professional portfolio managers. Professional portfolio managers also have the resources and access to companies, therefore they have the information that may not necessarily be available to others. According to EGDH (1993) mutual funds have been consistently underperforming the model on average, what this means is this supports the strong form of EMH, this is because  their underperformance on average shows that they were unable to exploit the information they had. Elton et al (1993) conducted a research on efficiency with costly information and they found out that on average they underperformed the model by 1.27%, this again offers evidence in support for the strong form of EMH.

Also a significant problem for investors and market observers is the information asymmetry between executives and investors. Cross secional variation in collecting and receiving data advantages and expenses leads to variation in data asymmetry.

Reducing data inequity has been a long-term objective in the US, leading the Securities Act of 1934 to the desire to decrease infrmation asymmetry. Required disclosure of economic information is required for capital markets to operate fairly and efficiently.

As everyove, whether an insider or an outsider, should have equal access to appropriate data, the notion of “fairness” is very crucial.

While some stand firm on regulation to reduce information asymmetry, the demand for data from investors and the desire for capital from entrepreneurs motivates the development and uncovery of personal data, offering another way to reduce the asymmetry of data.

Accounting scientists usually recognize the role of economic repoting in decreasing executives and investors ‘ data asymmetry. One argument for enabling executives to obtain data flexibly is that it enables executives to better communicate their understanding of the economic situation of their company in financial reports (Dechow, 1994).

A complicated issue related to testing EMH is Joint Hypothesis Problem: market efficiency must be tried jointly with some equilibrium pricing model portraying anticipated returns must be indicated. EMH is not a falsifiable hypothesis, it shows us how asset prices would behave under assumed conditions. Testing for this does not make sense as the financial market is so complex compared to the cut down conditions of perfect competition. The most that can be done at the moment is to be very cautious while interpreting the evidence that is presented as testing EMH.

In conclusion the strong efficient market hypothesis is a very complicated form as presented to us, it seems very unrelaistsic because it is not guaranteed that in regards to corporate insiders, the information they obtain from research is not going to be used to their own advantage. Due to their high position within the company they have easy access to information that is not available to the public therefore we can not trust that information will not be used to their own advantage. Either way policy makers have made restrictions on insider trading in order to regulate it to make sure that any insider trading taking place falls under legal requirement. Security analysts are not insiders, however they can attain information that the average investor would not be able to attain. Both investor classes have showed evidence that they can beat the model usin legal trading which goes against strong efficient market hypothesis. Professional portfolio managers is the only investor class that offers evidence in support of strong efficinet market hypothesis.

Reference list

  • Alajbeg, D., Bubaš, Z. and Šonje, V., 2012. The efficient market hypothesis: problems with interpretations of empirical tests. Financial theory and practice, 36(1), pp.53-72.
  • Chang, S., Suk, D., 1998. Stock prices and the secondary dissemination of information: The wall Street Journal’s ‘‘insider trading spotlight” column. Financial Review 33, 115–128.
  • Dechow, P., 1994. Accounting earnings and cash flows as measures of firm performance: the role of accounting accruals. Journal of Accounting and Economics 18, 3–42
  • Helland, E., Sykuta, M., 2005. Who’s monitoring the monitor? Do outside directors protect shareholders’ interests? Financ. Rev. 40 (2), 155–172
  • Manne, H.G., 1966. Insider trading and the stock . Free Press, New York.
  • Muller, K.A., Neamtiu, M., Riedl, E.J., 2012. Do managers benefit from delayed goodwill impairments? Working Paper. Pennsylvania State University
  • Womack, L., Michaely, R., 1996. Brokerage Recommendations.pp 1-2

Cite This Work

To export a reference to this article please select a referencing stye below:

Reference Copied to Clipboard.
Reference Copied to Clipboard.
Reference Copied to Clipboard.
Reference Copied to Clipboard.
Reference Copied to Clipboard.
Reference Copied to Clipboard.
Reference Copied to Clipboard.

Related Services

View all

DMCA / Removal Request

If you are the original writer of this assignment and no longer wish to have your work published on the website then please: