Top Banner
1 COVER PAGE OF THE PROJECT WORK TITLE OF THE PROJECT EFFICIENCY HYPOTHESIS OF THE STOCK MARKET CASE STUDY: GHANA STOCK EXCHANGE A PROJECT REPORT UNDER THE GUIDANCE OF Mr Daniel Odei Tetteh SUBMITTET BY CAMARA MOHAMED BINTOU IN FULFILLEMENT OF THE REQUIREMENT FOR THE AWARD OF THE DEGREE OF MBA IN FINANCE SMU SIKKIM MANIPAL UNIVERSITY DIRECTORATE OF DISTANCE LEARNING FEBRUARY 2011
113
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Page 1: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

1

COVER PAGE OF THE PROJECT WORK

TITLE OF THE PROJECT

EFFICIENCY HYPOTHESIS OF THE STOCK MARKET

CASE STUDY: GHANA STOCK EXCHANGE

A PROJECT REPORT UNDER THE GUIDANCE OF

Mr Daniel Odei Tetteh

SUBMITTET BY

CAMARA MOHAMED BINTOU

IN FULFILLEMENT OF THE REQUIREMENT FOR THE AWARD OF

THE DEGREE OF MBA

IN

FINANCE

SMU

SIKKIM MANIPAL UNIVERSITY

DIRECTORATE OF DISTANCE LEARNING

FEBRUARY 2011

Page 2: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

2

RESEARCH TOPIC

EFFICIENCY HYPOTHESIS OF THE STOCK MARKET

CASE STUDY: GHANA STOCK EXCHANGE

CAMARA MOHAMED BINTOU

MBA-FINANCE IN SIKKIM MANIPAL UNIVERSITY

EMAIL: [email protected]

Tel (00233)541675942

Page 3: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

3

ACKNOWLEDGEMENT

First and foremost, I would like to express my deepest sense of gratitude to the

Almighty ALLA H who has given me the opportunity, health and soundness of

mind to write this project work.

I am deeply indebted to my advisor Mr Daniel Odei Tetteh Whose expertise,

understanding, patience, motivation, enthusiasm, immense knowledge and his

constant support, added considerably to my experience. I appreciate his vast

knowledge and skills in many areas and without which this project would not be

possible. I could not have imagined a better advisor and mentor for this project.

I am heartily thankful to Madam Claudia……………. at the Ghana stock

exchange, whose encouragement, guidance and support from the initial to the final

level enable me to develop an understanding of the subject.

I owe my deepest gratitude to all my lecturers at Sikkim Manipal University and

all my colleagues.

Where would I be without my family and friends? To my father Elhadji KABA

CAMARA who put the fundament of my learning character, showing me the joy of

intellectual pursuit. To my mother BINTOU YATTASSAYE who raised me with

so much care and love. To all my brothers, sisters and friends for being supportive

financially and morally.

Page 4: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

4

DEDICATION

I dedicate this project to my family and my future wife Miss BINTILY

KONATE

Page 5: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

5

Bonafide Certificate:

BONAFIDE CERTIFICATE

Certified that this project report titled ―EFFICIENCY HYPOTHESIS OF THE

STOCK MARKET CASE STUDY GHANA STOCK EXCHANGE” is the

bonafide work of ―CAMARA MOHAMED BINTOU‖ who carried out the project

work under my supervision.

Gajendra Singh Manish Mittal

HEAD OF THE DEPARTMENT FACULTY IN CHARGE

Sikkim Manipal University of Health, Medical and Technological Sciences

Directorate of Distance Education

Ring Road opposite Busy Internet

www.smugh.edu.in

Page 6: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

6

EXECUTIVE SUMMARY

The efficient market hypothesis is one of the most controversial market theories in

finance, which was developed in the 1960s by Eugene Fama. According to fama

―an efficient market is defined as a market where there are large numbers of

rational, profit-maximizers actively competing, with each trying to predict future

market values of individual securities, and where important current information is

almost freely available to all participants. In an efficient market competition

among the many intelligent participants leads to a situation where, at any point in

time, actual prices of individual securities already reflect the effects of information

based both on events that have already occurred and on events which, as of now,

the market expects to take in the future.

The purpose of this paper is to determine whether the GSE is weak form efficient

and if it is possible to predict the future of the security prices, using all kind of

information to increase returns on the portfolio and consequently to beat the

market.

As a result of this study, we found that the Ghana stock exchange is weak form

inefficient .Which means that the prices can be predicted and some smart investors

can earn abnormal profits. This inefficiency is due to factors like the volume of

traded stock, the size of the market, lack of adequate knowledge of the market

from the investors.

To resolve this inefficiency, the market has to be large and liquid, the information

must be available in term of accessibility, the cost of the transaction must be cheap

and there should an efficient system of settlement. There should also be a

campaign to sensitize people about the stock exchange. The system of trading

should also be innovative.

Page 7: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

7

Tableau of content

TITLE PAGES

Acknowledgement………………………………………………………..III

Dedication………………………………………………………………..IV

Bonafide certificate……………………………………………………….V

Executive summary………………………………………………………V

Abstract ……………………………………………………………………1

Chapter 1…………………………………………………………………..2

Research questions…………………………………………………………2

Motivations………………………………………………………………….2

Justifications…………………………………………………………………3

Limitations of the study………………………………………………………4

Outline of the project…………………………………………………………4

Methodology…………………………………………………………………5

Background…………………………………………………………………..6

Previous studies……………………………………………………………..9

Performance of the GSE…………………………………………………….10

Importance of the stock exchange in the developing countries………………11

Page 8: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

8

Political situations in Ghana …………………………………………….13

Chapter 2

History and development of the financial market in Ghana ………………14

Structure of the Ghana stock exchange……………………………………..16

Role of Ghana stock exchange in the Ghanaian economic ………………….17

Challenges facing the Ghana stock exchange…………………………………18

Chapter 3

Trading system…………………………………………………………………21

Clearing and settlement………………………………………………………..27

Legal and regulatory framework……………………………………………….28

Regulations affecting foreign and non-resident investors……………………….28

Listing on the Ghana stock exchange…………………………………………….29

Chapter 4

Literature review…………………………………………………………………33

History of efficient market hypothesis…………………………………………....33

Market conditions consistent to efficient market hypothesis……………………..41

Types of efficiency………………………………………………………………..42

Forms of efficiency………………………………………………………………42

Early Models……………………………………………………………………..49

Page 9: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

9

Chapter 5

Technical analysis and efficient market hypothesis………………………………62

Fundamental analysis strategy for predicting the stock returns………………….67

Market anomalies……………………………………………………………….72

Behavioral finance and efficient market hypothesis……………………………82

Chapter 6

Data and research methodology……………………………………………….88

Reasons behind inefficiency……………………………………………………98

Solution for inefficiency………………………………………………………..99

Chapter 7

Conclusion and recommendation……………………………………………..101

Page 10: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

10

LISTS OF TABLES

Table 1 TABLE

Table 2 REGRESSION TABLE

Table 3 ANOVA

Table 4 REGRESSION COEFFICIENT TABLE

Page 11: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

11

LIST OF ABBREVIATION

EMH efficient market hypothesis

GSE Ghana stock exchange

CSD central securities depository

ATS Automated trading system

GATS General automated trading system

CAT Continuous auction trading system

LDM licensed dealing member

GSE-CI Ghana stock exchange composite index

GSE-FSI Ghana stock exchange financial stock index

OCT over the counter market

FOL First official list

SOL Second official list

EPS Earning per share

BM Book-to-Market value

ROA Return on Asset

GSM Ghana stock market

Page 12: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

12

Page 13: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

13

There is an old joke among economists which goes like this: “two economists were

walking along the street. One of them saw a note of GHc 10 cedis lying down at

the middle of the road and leans down to retrieve it. The second one said” don’t be

ridiculous because if that were a genuine GHc 10 someone would have picked it up

ABSTRACT

This paper is an attempt to investigate the validity of weak form efficiency market

hypothesis on Ghana stock exchange. A study conducted by frimpong Joseph

Magnus concluded that Ghana stock exchange is weak form inefficient and another

study conducted by Kofi A. Osei also confirmed that GSM is inefficient with

respect to annual earnings information releases by the companies listed in the

GSE.This paper provides a brief description of the Ghana stock exchange and

gives the meaning of efficient market. The regression coefficient is applied on the

Ghana stock exchange all-share index to carry out the test.

If a capital market is efficient the price of the stock should reflect the knowledge

and expectation of the investors and consequently no investor should be able to

receive an abnormal return since there is no way that he could know something

that has not been already reflected in the price of the stock. The main findings of

this project do not support the weak form efficient market hypothesis in the Ghana

stock exchange. The GSE is weak form inefficient which means that some

investors are able to predict the price of the security and get excess returns.

Page 14: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

14

Chapter 1

INTRODUCTION

RESEARCH QUESTION

This paper aims at investigating the weak form efficiency of the Ghana stock

exchange and also to determine whether the theoretical ideas are pertaining to the

real life. In this context the Ghana stock exchange will be tested and the results

obtained would be used to answer the following questions:

1- Is Ghana stock exchange weak form efficient?

2- How far does the weak form efficiency hold true in the functioning of the

Ghana stock market?

3- Can the security prices be predicted in the Ghana stock market?

4-can there be investors with information which is not reflected in the security

prices?

5-Is Ghana stock market fully reflecting the information?

6-How is the Ghana stock exchange reacting to new information?

MOTIVATIONS OF THE RESEARCH

As stated earlier, the objective of this study is to test the weak form of efficiency in

Ghana stock exchange which has not been deeply investigated and studies about

the weak form are very few. This study will help the investors to know how the

Page 15: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

15

Ghana stock market works, how to invest in the Ghana stock exchange and the

importance of an efficient market such as encouraging share buying, giving correct

signals to managers and allocating the resources. In the objective of testing the

weak form efficiency some theories will be tested and some aspects of the Ghana

stock market will be looked at in order to achieve the stated objective.

JUSTIFICATION OF THE RESEARCH

This project will be added to the body of knowledge by making a special case on

GSE on the subject of efficiency hypothesis of the stock market in its weak form.

This study attempts to investigate the weak form efficiency and ways of improving

the GSE to become a world class exchange.

This study will inform the investors about how to invest in the stock market, the

benefits that they can derived from the stock market and also roles of the

government in improving the efficiency of the stock market.

The Ghana stock market has been operating for some years now. The movement of

the market is measured by the GSE-All share index.

The GSE is an emerging capital market where many of the investors do not have

adequate education about investing in the stock exchange. Investing is not a game

of luck or chance but it requires knowledge about securities, the stock market and

the economic indicators. So there is a need for them to understand how the stock

exchange works and how its responds to the changes in the economic variables

such inflation, GDP, interest rate and others. Also arouse investors‘ awareness

about the opportunities available in the stock market and how to exploit them.

Page 16: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

16

LIMITATIONS OF THE STUDY

The aim of this study is to investigate the weak form efficiency of the Ghana stock

exchange. Other forms of the market efficiency have not been taken into account.

The time for this study is limited to the period of January 2007 to December 2008

excluding the holidays and non-working days.

THE OUTLINE OF THE PROJECT

This project work consists of seven chapters. Chapter 1 is the introduction which

deals with abstract, research question, motivation, justification, methodology,

background of the study, previous studies, underlining assumption, performance of

the GSE, importance of the stock market in the developing countries and the

political situation in Ghana.

Chapter2 deals with history and development of the financial market in Ghana,

structure of the GSE, role of the GSE in the Ghanaian economy and challenges

face by the GSE. Chapter 3 deals with the trading system, legal regulatory

framework, the listing requirement and clearing and settlement. Chapter4 deals

with literature review where we define the EMH, talk about the forms and types of

efficient market, market conditions consistent with efficiency and the early models.

Chapter 5 describes other techniques like fundamental and technical analysis,

market anomalies and behavioral finance. Chapter 6 deals data and research

methodology, reasons behind inefficiency and the solutions for efficiency and

chapter 7 deals with conclusion and recommendation for further research.

Page 17: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

17

METHODOLOGY

The primary data was collected through interview and questionnaires sent to the

various brokerage houses and interview with the staff and management of the GSE.

The secondary data was collected through the website of the GSE by using

information sources like press releases, half year and annual reports and others.

Other information was collected through the use of the library of the GSE and

other reading materials. In addition to information collected through the internet.

Some information like the Ghana stock exchange all-share index for the period of

January 2007 to December 2008 was collected through the website of the security

and exchange commission in Ghana. In addition to other relevant information

Page 18: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

18

BACKGROUND OF THE STUDY

The stock market is an organized public market for the trading of a company stock

and derivatives at an agreed price. The stock market is different from the stock

exchange which is an entity that brings together buyers and sellers of a stock. They

buy and sell securities such as shares and bonds etc... Prices on the stock market

are determined by the forces of the demand (what people are willing to buy) and

supply (what sellers have available for sale).

The market is supervised by officials of the stock exchange as well as the

Securities and Exchange Commission.

On this market, individuals and companies can buy shares and bonds and other

securities of the companies through licensed dealing members or stockbrokers of

the Ghana stock exchange. The buyers include people residing in Ghana as well as

non-residents. It includes Ghanaians and foreigners. Adults (people above 18

years) can buy shares for themselves and also buy in trust for their children.

The Ghana stock exchange is the cornerstone of the Ghanaian capital market.

The idea of establishing a stock market in Ghana lay on the drawing board for

almost two decades prior to its implementation. In February 1989, the issue of

establishing a stock exchange moved a higher gear when a 10 – member National

Committee, under the chairmanship of Dr. G.K Agama, then governor of the Bank

of Ghana, was set up by the government.

The work of the committee was to consolidate all previous work connected to the

stock Exchange project and to fashion out modalities towards the actual

establishment of the Exchange. As a result of the work of the committee, the stock

exchange was established in July 1989 as a private company limited by guarantee

Page 19: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

19

under the companies‘ code of 1963. It was given recognition as an authorized stock

exchange under the stock exchange act of 1971 (act 384) in October 1990. The

council of the exchange was inaugurated on November 12, 1990 and trading

commenced on its floor the same day. The exchange changed its status to a public

company limited by guarantee in April 1994.

The exchange was set up with the following objectives:

1- To provide the facilities and framework to the public for the purchase and

sales of bonds, shares and other securities,

2- To control the granting of quotations on the securities market in respect of

bonds, shares and other securities of any company, corporation, government,

municipality, local authority or other body corporate,

3- To regulate the dealings of members with their clients and other members,

4- To co-ordinate the stock dealing activities of members and facilitate the

exchange of information including prices of securities listed for their mutual

advantages and for the benefit of their clients,

5- To co-operate with associations of stockbrokers and stock exchanges in

other countries, and to obtain and make available to members information

and facilities likely to be useful to them or to their clients.

Since its inception, the GSE's listings have been included in the main index, the

GSE All-Share Index. In 1993, the GSE was the sixth best index performing

emerging stock market, with a capital appreciation of 116%. In 1994 it was the

best index performing stock market among all emerging markets, gaining 124.3%

in its index level. 1995's index growth was a disappointing 6.3%, partly because of

high inflation and interest rates. Growth of the index for 1997 was 42%, and at the

end of 1998 it was 868.35 (see the 1998 Review for more information). As of

Page 20: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

20

October 2006 the market capitalization of the Ghana Stock Exchange was about

111,500bil cedis($11.5 billion). As of December 31 2007, the GSE's market

capitalization was 131,633.22bil cedis. In 2007, the index appreciated by 31.84%

(see the ―Publications‖ section on the GSE‘s website for more information).The

manufacturing and brewing sectors currently dominates the exchange. A distant

third is the banking sector while other listed companies fall into the insurance,

mining and petroleum sectors. Most of the listed companies on the GSE are

Ghanaian but there are some multinationals. Although non-resident investors can

deal in securities listed on the exchange without obtaining prior exchange control

permission, there are some restrictions on portfolio investors not resident in Ghana.

The current limits on all types of non-resident investor holdings (be they

institutional or individual) are as follows: a single investor (i.e. one who is not a

Ghanaian and who lives outside the country) is allowed to hold up to 10% of every

equity. Secondly, for every equity, foreign investors may hold up to a cumulative

total of 74% (in special circumstances, this limit may be waived). The limits also

exclude trade in Ashanti Goldfields shares.

These restrictions were abolished by the Foreign Exchange Act, 2006

(Act723).There is a 8% withholding tax on dividend income for all investors.

Capital gains on securities listed on the exchange will remain exempt from tax

until 2015. The exemption of capital gains applies to all investors on the exchange.

There are no exchange control regulations on the remittance of original investment

capital, capital gains, dividends, interest payments, returns and other related

earnings. Potential changes at the exchange include the introduction of automated

trading and the listing of some state banks. The Bank of Ghana plans the

development of mutual funds, unit trusts and municipal bonds at a subsequent date.

These changes are aimed at making the exchange more relevant, efficient and

Page 21: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

21

effective. The exchange was also involved in preparing the draft law on collective

investment vehicles.

PREVIOUS STUDIES

Some studies have been done in order to test the efficiency of the GSE. First Osei

in 2002 conducted a study on the GSE. The objective was to test the response to

annual earnings announcement on the GSE. The study concluded that the GSE was

inconsistent with efficient market hypothesis with regard to earning announcement.

Frimpong in 2008 test the weak form efficiency on the GSE and rejected the null

hypothesis in concluding that the GSE is weak form inefficient.

As a result of this study, we can say is not a waste of time for an investor to

look for an under-valued or over-valued stock. Some hardworking investors

can reap abnormal profits and also some smarts investors can outperform the

market or consistently beat the market.

This inefficiency has a positive effect on the investors because it can allow

them to increase their returns, to know in which company invests and save

their investment.

The negative effect of this inefficiency is that investors will know about the

under-valued stocks and give low price for them which will discourage the

managers and the shareholders. Sometimes it will lead to the non-

performance of the company which will even discourage other companies to

list in the GSE.

Page 22: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

22

UNDERLINING ASSUMPTIONS

This study investigates the weak form efficiency with focus on the Ghana stock

exchange. It explains how the trade, listing, clearance and settlement take place in

the Ghana stock exchange and also how an investor foreign or national can invest

and reap profits from the Ghana stock exchange.

The implicit assumption is that the Ghana stock exchange should be efficient for

investors to make inform decision and not allowing some investors to get excess

returns without accepting extra cost. Hence the topic ―efficiency hypothesis of the

stock market‖

PERFORMANCE OF THE GHANA STOCK EXCHANGE

The benchmark measure of performance of the Ghana stock exchange was the

Ghana stock exchange all-share which is now the GSE-composite index (GSE-CI).

From 1990 to 2009 this index has increased from 77.25 points to 5,572.34 points.

Despite the global financial crisis, the GSE in 2008 has performed well by

recording 10,431.64 points. In 1993, the GSE emerged has the 6th

best performing

emerging stock market with an impressive return of 114%.

In 1994, in a study conducted by Birinyi Associates, a research group in the USA,

the GSE came out as the best performing market among all the emerging markets

with a gain of 124%.

In 2008, the GSE was the world‘s best performing stock exchange despite of the

world global financial crisis with a gain of 58% but in the subsequent year the

performance was poor with a loss of 47%.

Page 23: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

23

In February 18, 2011, the stock inched down to 0.86 points for the fourth straight

session to close at 1,048.78 points. The year to now stands at 4.88 percent.

The GSE financial stock (GSE-FSI) which tracks the performance of listed stocks

was also down 0.54 points to 1,036.56 points from 1,037.10 points at the previous

session, with a year-to-date change of 3.66 per cent.

There were three price changes, a gainer and two losers. Standard Chartered Bank,

the sole gainer for the session, was up GH¢0.04 to GH¢46.79. Decliners for the

session were Fan Milk Limited, which dipped GH¢0.02 to GH¢2.50 and Ghana

Commercial Bank fell GH¢0.01 at GH¢2.49.

Market Capitalization closed the session marginally lower at GH¢20,124.29

million from GH¢20,128.54 million. Total shares traded are 210,775 shares, valued

at GHC96, 469.(the Ghanaian journal February 18, 2011).

IMPORTANCE OF THE STOCK EXCHANGE IN THE DEVELOPING

COUNTRIES

One way of achieving economic growth in the developing countries is through an

efficient financial market that will channel resources for productive investments,

mobilize foreign capital and also provide funds to increase the productivity of the

national industries and reduce poverty by creating more jobs.

The financial stock market serves as a veritable tool in the mobilization and

allocation of savings among competing uses which are critical to the growth and

efficiency of the economy (Alile, 1984). Other researchers have showed that the

stock market development positively influences the economic growth (Korajczyk,

1996, Levine and Zervos, 1998).

Page 24: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

24

Levine (1991) showed a positive relation between financial stock market and

economic growth by issuing new financial resources to the firms. The financial

stock market facilitates higher investments and the allocation of capital, and

indirectly the economic growth.

An efficient stock market contributes to attract more investment by financing

productive projects that lead to economic growth, mobilize domestic savings,

allocate capital proficiency, reduce risk by diversifying, and facilitate exchange of

goods and services (Mishkin 2001; and Caporale et al, 2004). Further, Levine and

Zervos (1998) found strong statistically significant relationship between stock

market development and economic growth. The result of Filer et al. (1999)‘ studies

show that there is positive causal correlation between stock market development

and economic activity. Many other researchers argue that there is a positive

correlation between financial development and economic growth

(Goldsmith, 1969; Shaw, 1973; McKinnon, 1973 and King & Levine, 1993). They

found that financial development is an important determinant of future economic

growth of a country. Atje and Jovanovic (1989) found also a significant impact of

the level of stock market development and bank development. Joseph

Schumpeter (1912)‘s book was the most important and thorough one of the earlier

contribution on financial development and economic development. For him,

financial development causes economic development – that financial markets

promote economic growth by funding entrepreneurs and in particular by

channeling capital to the entrepreneurs with high return projects. Therefore the

GSE also needs to be efficient so that it can contribute the growth of the Ghanaian

economy.

Page 25: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

25

POLITICAL SITUATIONS IN GHANA

One of the major differences between efficient and inefficient market is the

political situation in the country. Political instability sometimes results in stock

market being manipulated by the government which will cause the inefficiency of

the stock market.

When the government is controlling the stock market all the information will not

be provided to the public therefore the decision making process will be difficult

and the decision base on this information will not be accurate.

The prices will reflect neither the true value of the securities nor other information

in the market. This will result in the stock market being inefficient.

Also as a result of this political instability, investors will not be motivated to invest

neither in the Ghana stock exchange nor in the capital market by fear of losing

their investments. Therefore, we need a stable political situation as one of the

conditions of the market being efficient.

Page 26: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

26

CHAPTER 2

A-HISTORY AND DEVELOPMENT OF THE FINANCIAL MARKET IN

GHANA

The economy of Ghana underwent economic reforms in 1983 at the time when the

country was collapsing with high inflation around 123%, large exchange rate

swings and negative real interest rate. These reforms were aiming at liberalizing

the Ghanaian economy. So the government of Ghana with the help of the World

Bank had launched the structural adjustment programme to address the

deterioration problems in the financial sector.

As part of the reforms, monetary policy was instituted and market for securities

was created. In 1986 a weekly auction in treasury bills was introduced. Again the

bank of Ghana bills was also introduced in 1988 to take care of excess liquidity in

the system especially in the rural areas and also to provide an avenue of investment

for banks (bank of Ghana consultation paper October 2007).

The Ghana stock exchange was established as part of these reforms. The GSE

though incorporated in July 1989, the normal operations started on November,

1990.

One main objective of establishing the GSE was to enable corporate institutions

and government to raise quick capital to accelerate development in order to reduce

undue reliance on donors.

After establishing the GSE in November 1990 with only 12 listed companies and

one government bond, the market capitalization within two years of operation

increased from GH ¢3 billion in 1991 GH¢4.3 billion in 1992 while the listed

companies increased to 15. With a drop of 46.58% in the GSE All-share index, the

Page 27: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

27

GSE ended the year 2009 as the least performing market in Africa. In the previous

year 2008, the gain in the GSE All-share index was 58% and this moved Ghana

ahead of all the African markets.

The market capitalization of the exchange declined by 11% to end the year at

GH¢15.94billion down from GH¢17.90billion in 2008. The decline in the value of

Ghana‘s market was mainly due to price depreciation.

According to Bank of Ghana report, for the fifth consecutive month, headline

inflation went up from 12.8% in January to 13.2% in February and this was due to

prices increased in the first two months of the year. This increased, the report said

was driven by surges in food prices and rising crudes oil prices. (Bank of Ghana

Monetary Policy report: vol 3 no 2: 2008 1).

In this market condition one would confirm the theory put forward by Samuelson

and Mandelbrot followed by Eugene Fama, which is ―Efficient Market

Hypothesis‖: they said that when markets are working properly, then all public

information regarding an asset will be incorporated immediately into the price.

The GSE was adjudged ―the most innovative African stock exchange for 2010‖ at

the African investors prestigious annual index series awards held at the new York

stock exchange on Friday, 17th September 2010.

The African investor index series awards are the only international pan-African

that recognize and reward Africa‘s institutional investors, stock exchanges, best-

performing listed companies, stockbrokers and capital market regulators. The

awards assessed performance between April 2009 and April 2010 out the group of

seven stock exchanges nominated (www.gse.com)

Page 28: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

28

In their objective of being efficient and to position the GSE to compete favorably

on the international market as well as attracting more investors in the domestic and

international market, the GSE has adopted the automated trading system(GATS)

which is a computer base trading that automatically submits trades onto the trading

system. The system is designed to match orders placed by the stockbrokers to buy

and sell shares in an electronic order book and these orders are automatically

matched i.e the system determines who buys what at which price and from which

seller

B-THE STRUCTURE OF THE GHANA STOCK EXCHANGE

The exchange is governed by a council with representation from licensed dealing

members, listed companies, the banks, insurance companies, money market and

the general public. The Managing Director of the exchange is an ex-officio

member. The council sets the policies of the exchange and its functions include

preventing fraud and malpractices, trading and settlement and maintaining good

order among members, regulating stock market business and granting approval for

listing, maintaining public confidence in the market and promoting the exchange. It

has the power to suspend or expel any licensed dealer member that contravenes the

rules of the exchange. The council‘s membership includes some of the most

distinguished and competent people in the Ghanaian commerce, industry, finance

and public service.

Page 29: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

29

ROLES OF GHANA STOCK EXCHANGE IN THE GHANAIAN ECONOMY

The GSE plays the following roles in the Ghanaian economy:

-Raising capital for businesses

-Major link between companies and governments with capital need and the public

with savings to invest.

-The growth of the economy by mobilizing savings for investment

-Creation of jobs

-Promote savings and investment habit

-Provide liquidity to investors

-Establish a pricing mechanism for financial asset

-Enhance corporate transparency or corporate governance

-Improved share appreciation

-Enhance volumes of securities traded

-Facilitating company growth

-Profit sharing

-Barometer of the economy

-It provides a market place for trading

-Provide a powerful tool for the government and policy makers to manage

economies

-Improve share price appreciation and enhance volumes of securities traded

Page 30: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

30

THE CHALLENGES FACE BY THE GHANA STOCK EXCHANGE

The Ghana stock exchange is facing the following problems:

First is the political instability that has been discussed in the earlier section.

The second is the macroeconomic instability or volatility. The Ghana‘s economy

has been characterized by high inflation, high interest rate and large exchange rate

swings as stated by the Bank of Ghana Monetary Policy report: (vol 3 no 2: 2008

1). These variables when they are high, they discourage the investors to invest in a

specific country because they can‘t diversify the risk and also are not sure of

getting their investment back.

Another problem facing the GSE is due to the stock exchange itself. According to

Benimadhu (2003), among the exchange specific issues affecting stock markets in

Africa are low level of liquidity, few listed companies and the small size of the

exchange as well as efficiency. We assume that the stock exchanges in Africa face

the same challenges. Other factors which has stifled the development of the GSE

relates to the absence of a strong and active domestic investor base, led by

institutional investors such as pension funds and insurance companies. Clearing,

Settlement and Trade systems as well as trading infrastructure should be

ameliorated.

The following points need to be noted carefully:

1-Investors confidence

Fluctuation in interest rates, high rate of inflation and instability of the cedi made it

difficult to predict the future of the capital market and because of this, the investors

Page 31: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

31

find it difficult to invest or borrow money from the market. According to the bank

of Ghana in his report, inflation went up to 12.8% in January 2008 to 13.2% in

February 2008. The report attributed the price increased to the increased in food

prices and the rising crude oil. (Bank of Ghana monetary policy report: Vol 3 No 2

2008 1)

2-Unpredictability of the market

In terms of instruments traded and the number of participants in the market, the

capital market in Ghana is relatively small as compared to that of the stock

exchange in America or Paris or UK. Fluctuation of the economic indicators and

instability of the cedi have made very difficult for the investors to predict the

Ghanaian capital market. An evaluation of the real return on the Ghana stock

exchange by the Bank of Ghana revealed that ― the total annual real return on the

stock listed on the Ghana stock exchange have followed an undulating pattern

since 1991 falling every two years and rising every two years‖.(Bank of Ghana

report)

3-Price forecast

The capital market in Ghana has been characterized by unstable price. Prices of

goods and services are volatile and the same for inflation, interest rates and

exchange rates. This condition will make it difficult for predicting the share prices

which will confirm the theory of efficient market hypothesis.

Some positive changes

Re-denomination

According to Ghana news agency report in 2008, the re-denomination of the

Ghanaian cedi in july 2007 was predicted as something which will strengthen the

Page 32: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

32

financial market in Ghana. This is because it will reduce high transaction costs and

also reduce the inconvenience and high risk in carrying loads of currency for

transaction purposes. It would further ensure compatibility with data processing

software and the strain on payments system, particularly Automated Teller

Machine (ATMs) and above all it would reduce the difficulties in maintaining

financial and statistical records.

Foreign investors

Non-resident foreign investors can now hold more than 10% of any security listed

in the stock market which was not the case few years back. They can trade in

money market instruments and also maintain a foreign currency account with the

local banks which can be credited with transfer in foreign currency from abroad or

other foreign currency account. (www.ghanaweb).

Page 33: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

33

Chapter 3

A-TRADING SYSTEM

1-Principles of trading

The purpose of the Ghana stock exchange is the determination of the price of the

securities in a functional and efficient market, where all parties to the market have

simultaneously at their disposal sufficient information as a basis for price

formation.

Procedure that is contrary to good conduct shall not be employed in securities

trading.

A licensed Dealing Member shall maintain confidence in the market through it

activities.

A licensed Dealing Member must not take measures that are designed to distort the

price level or the number of securities, or any measures that do not correspond to

the form or intent of a legal act.

A licensed Dealing Member shall carefully follow the principles and rules

pertaining to trading.

Trading is carried out on the floor of the exchange under the continuous Auction

Trading system (CAT). Over the counter trading is however allowed in Ashanti

Goldfield Company‘s shares. Trading is done in lots of 100 shares. The automated

trading on the Ghana stock exchange is done through three alternative levels of

access, namely

1-on the trading floor of the Ghana stock exchange

2-At the office of the stockbroker through the wide Area Network

Page 34: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

34

3-Through the internet

When an investor instructs his stockbroker to buy or sell a particular security, the

broker will enter the order on his terminal using any of the three means and the

order will instantly be routed electronically to the stock exchange‘s ATS

(automated trading system). The system automatically matches the orders resulting

in trades. The GATS records the sale, quantity, buyer and seller and time of trade.

All these are done under the supervision of the Ghana stock exchange.

The Ghana Stock Exchange (GSE) has begun a new arrangement for a "continuous

auction trading" on trial basis for eight equities listed on its counters.

The new arrangement, which started two weeks ago, allows the Exchange to trade

for longer hours and forms part of measures to address difficulties faced in the use

of the current trading system known as the 'Call Over System'.

Equities involved in the new arrangement were chosen at random to give all listed

companies a chance to benefit from the trial run, which will last for three weeks.

If successful, the new arrangement will cover the rest of the equities after an

assessment.

Equities picked for the trial are British-American-Tobacco Company (BAT),

Enterprise Insurance Company (EIC), Fan Milk Limited (FML), Ghana

Commercial Bank (GCB), Guinness Ghana Limited (GGL), Mobil Ghana Limited,

Produce Buying Company (PBC) and Unilever Ghana Limited (UNIL).

The General Manager of GSE, Francis Tweneboa, told the Ghana News Agency

Page 35: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

35

(GNA) that the exchange had experienced some difficulties in the current Call over

System.

This system allows offers and bids for only one stock at a time and does not make

room for clients to bid to their advantage.

With the Call over System, names of the stocks are shouted for offers and bids. If a

client wishes to make a transaction after his chance elapses, he or she has to wait

until the next round to make a match.

In the new system, boards will be provided for the quotation or display offers and

brokers can match orders as and when it favours their clients.

Tweneboa said whereas the Call over System lasts for about two hours, the new

arrangement would continue for about six hours from 1,000 hours to 1,600 hours.

The closing time would also give brokers enough room to make settlements.

Yofi Grant, an Executive Director of Databank Brokerage Limited, lauded the new

arrangement, saying it is an attempt to modernise activities of the GSE.

"The Call over System has become obsolete and is a far cry from what exists on

international markets," he said, commending its potential to allow brokers to talk to

clients during trading on the floor.

Grant said brokerage firms agree to the new arrangement, which will serve as a

pre-cursor to electronic trading to enable the Ghana bourse to be part of

Page 36: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

36

globalisation.

He said, however, that modernisation of activities on the GSE must be gradual to

allow the smaller of the 12 brokerage firms who trade on the floor to catch up with

the pace in terms of expansion of offices, clients and expansion of the trading floor

OFFICIAL TRADING HOURS

Trading in approved securities, as defined by the listing rules, shall be limited to

the hours when the floor is open for the transaction of business.

There will be no trading in approved securities on the floor or anywhere else

before or after the official dealing hours, as defined by the council from time to

time, unless the council has expressly granted an exemption in which case trading

shall be done strictly within the conditions prescribed by the council.

Dealing hours was as follows:

-Pre-opening period 09.30 GMT 10.00 hrs GMT

-Open AUCTION 10.00 hrs GMT and

-Regular trading 10.00 hrs GMT -12.00 hrs GMT

According to the Business news of Tuesday, 4 January, 2011, the Ghana Stock

Exchange (GSE) has

extended its daily trading hours from three hours to five hours

effective January 4, 2011. The new trading hours shall be between 10.00 hrs and

Page 37: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

37

15.00 hrs

GMT instead of from 10.00 hours to 13.00 hours. A statement by the Exchange on

Tuesday said the change in trading hours was to afford dealers increased contact

hours with their clients during the trading day. It is also meant to afford non-

resident investors in time zones different from Ghana, greater opportunity to reach

out to their local brokers, it added. "It is our expectation also that the extended

trading hours will help improve liquidity in the market place," the statement said.

TYPES OF SECURITIES TRADED

Ordinary shares 35

Preference shares 1

Debt securities corporate 2

Government

2 years 56

3 years 36

5 years 3

INDEX

An index is a numerical value used to measure changes in a variable or group of

variables. The index is set of hypothetical or numerical level on the base period or

starting point against which a percentage change can be compared to at any

particular point of time.

Page 38: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

38

The stock market index is a specialized tool used essentially to capture the overall

performance of the stock market. It can also be employed to measure how a given

equity or bond portfolio is performing. If an investor owns more than one stock, it

is cumbersome to follow each stock individually to determine the composite

performance of the portfolio.

The stock index will reveal the overall trend in the performing of the market. It

also shows the stock price movements.

The Ghana stock exchange has introduced a new method of calculating closing

prices of equities on the market with effect from January 4, 2011. Closing prices of

listed equities will be calculated using the volume weighted average price of each

equity for every given trading day.

GSE has also published two new indices, namely the GSE composite index (GSE-

CI) and the GSE financial stock index (GSE-FSI)

*GSE composite index (GSE-CI)

The calculation of the GSE composite index will be based on the volume weighted

average closing of all listed stocks. All ordinary shares listed on the GSE are

included in the GSE-CI at total market capitalization. The base date for the GSE-

CI December 31, 2010 and the base index value is 1000.

*GSE financial stock index (GSE-FSI)

This index will have its constituents as listed stocks from the financial sector

including banking and insurance sector stocks. All ordinary shares of the financial

stocks listed on the GSE are included in the GSE-FSI at total market capitalization

except for those stocks which are listed on other markets. The base date of the

GSE-FSI is also December 31, 2010 and the base index value is 1000.

Page 39: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

39

The new indices will be published on each trading day beginning January 4, 2010.

B-CLEARING AND SETTLEMENT

Clearing is defined as ―the process of transmitting, reconciling and, in some cases

confirming payment orders or security transfer instructions prior to settlement‖

(BIS, 2003, p.13). Whereas settlement is described as ―the completion of a

transaction, wherein the seller transfers securities or financial instruments to the

buyer and the buyer transfers money to the seller‖ (BIS, 2003, p.45). The objective

for clearing and settlement process is that the system is prompt and reliable as well

as cost-effective and convenient to use. (Guadamillas & Keppler, 2001, p.19)

Clearing and settlement of securities transactions in listed securities shall be

conducted at the premises of the exchange or as may be determined by the central

securities depository (CSD) act or the exchange.

The exchange in conducting the clearing and settlement business shall incur no

other liability or responsibility for the conduct of such business other than seeing to

an orderly conduct of the business until the central securities depository

commences clearing and settlement for listed securities.

The clearing and settlement for a trading session(T) shall take place three business

days after the related trading session which is (T+ 3) at 11.am or within a given

time frame that the exchange shall specify by notice of amendment of this rule.

Settlement is manual but centralized. Currently, the settlement period is T+3

(business days). It is also delivery versus payment. The seller (stockbroker) of a

security is responsible for the validity of all documents delivered. The exchange

has set up a clearing house. All LDM (licensed dealer member) are members of the

Page 40: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

40

clearing house. They together with the exchange have accounts with the settlement

bank. On settlement day, the clearing house collects (debits) the bank account of

the LDMs who have bought securities and pays the amount collected into an

account of the clearing house. LDMs who sold securities are next paid or credited

with the amounts due to them move to the buying LDM in the Ghana stock

exchange depository.

C-LEGAL OR REGULATORY FRAMEWORK

Legislation

- The company code, 1963, (act 179)

- The security industry law, 1993 PNDCL 333

- Securities and exchange commission regulations 2003 1728

- Act 1695 GSE regulations/rules

- Stock exchange (Ghana stock exchange)

- Listing regulations 1990 LI 1509

- Stock exchange (Ghana stock exchange)

- Membership regulations 1990 LI1509

- Trading and settlement rules

D-REGULATIONS AFFECTING FOREIGN AND NON-RESIDENT

INVESTORS

Exchange control permission has been given to non-resident Ghanaians and

foreigners to invest through the exchange without any prior approval. However,

one external resident portfolio investor (whether individual or institution) can hold

only up to 10% of any security approved for listing on the exchange. Furthermore,

Page 41: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

41

the total holdings of all external residents in one listed security shall not exceed

74%

Ghanaians externally resident and foreigners resident in Ghana though may invest

any limit. The limits also apply in the case of AGC and PBC shares.

There is free and full foreign exchange remittability for the original capital plus all

gains and related earnings.

There is a 10% withholding tax (which is also the final tax on the dividend income)

for all investors both resident and resident. Capital gains on the listed security are

exempt from tax until November 2005.

LISTING ON THE GHANA STOCK EXCHANGE

A company is said to be listed on Ghana stock exchange when its securities are

approved to be bought and sold on the stock exchange. Newly issued shares cannot

be traded on the OCT (over the counter) market before getting listed on the GSE.

In order to get your newly shares listed on the GSE, you need to communicate this

intention early to the GSE and work with the exchange so that your prospectus will

satisfy the exchange‘s listing requirements before the public floatation.

A-Requirements for listing

There are certain requirements that the company must meet in order to qualify for

listing on the Exchange. These requirements are stipulated in GSE rules Book.

Many companies will meet these qualifications.

Page 42: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

42

To make it possible for many companies to list on the exchange, there are two lists

with fairly easy requirements:

a- The first official list (FOL)

b- The second official list (SOL)

The approval of an application for the listing securities on the stock exchange is

solely within the discretion of the council of the Ghana stock exchange.

The requirements are as follows:

1-listing requirements for shares

Minimum stated capital

The company must have a stated capital after the public floatation of at least GHc

1million in the case of an application relating to the first official list and GHc

0.5million for the second official list.

Minimum public float

Shares issued to the public must not be less than twenty-five percent (25%) of the

number of shares issued by the company unless reasonable justification is provided

for a smaller percentage.

Payment of shares

Shares must be fully paid for. Except in very exceptional circumstances, the

exchange will refuse listing in respect of partly paid shares

Spread of shares

Page 43: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

43

The spread of shareholders existing at the close of an offer should be in the GSE‘s

opinion adequate with at least 100 shareholders after the public offer.

2-listing requirements for debt securities

A company seeking the admission of debt securities to the GSE may be considered

for such admission if the security concerned has a total issue amount of not than

GHc 1million face value or there are at least 50 holders of such security.

In the case of government securities, there is no prescribe minimum in respect of

either amount issue or number of holders to permit admission to the GSE‘s list

Debt securities for which listing are sought shall be created and issued pursuant to

a Trust Deed duly approved by Securities and Exchange Commission.

ADDITIONAL REQUIREMENTS FOR LISTING

The following additional requirements apply to both applications for listing of

equities and debts securities.

Period of existence

For a company‘s securities(whether equity or debt) to be eligible for admission to

the GSE, the company must have published or filed audited accounts in accordance

with the companies code, 1963, (act 179) for at least three years immediately

preceding the date of its application for listing. For the SOL, in respect of shares,

the period is one year.

Profitability

Profitability must have been reasonable through the periods stated above or the

company must have strong potential to be profitable.

Page 44: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

44

Conditions relating to Directors and Management of Applicant

There must have been continuity in the management of a company seeking

admission to the GSE.

The character and integrity of the directors and management of the company will

be among the criteria taken into account by the council of the exchange.

At least 50% of the board must be non-executive directors and this number at least

two (2) or 25% shall be independent

Page 45: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

45

Chapter 4

Literature review

HISTORY OF EMH

IN GEORGE Gibson‘s book the stock markets of London, Paris and New York,

published in 1899; we see one the first reference to market efficiency. He says, ―In

an open market, when the shares become publically know, the value they obtain

may be considered to reflect the most intelligent appreciation possible”.

Louis jean Baptist Alphonse Bachelier also made reference to market efficiency in

his PhD mathematics dissertation paper to the University of Sorbonne. In his

opening paragraph Bachelier recognizes that “past, present and even discounted

future events are reflected in market price, but often show no apparent relation to

price changes”. And he continue to say that ―if the market, in effect, does not

predict its fluctuations, it does access them as being more or less likely and his

likelihood can be evaluated mathematically‖. So according to this theory the

mathematical performance expectations are useless. Therefore neither buyers nor

sellers can make systematic profit and also the price in such market follows

uncertain fluctuation.

Bachelor‘s work was made known to Paul samuelson through Leonard j. savage

who describes efficiency in terms of winning formula.

From 1932-1953 the trio of cowls, working and kendall stir things up by

challenging the ability of professionals to anticipate stock market prices, since they

essentially would have uncertain progress. We must say that on Wall Street, there

is quite an industry of advice to investors based on the forecasts of specialists.

Page 46: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

46

In 1933 Alfred cowls publishes in econometrica ―can stock market forecasters

forecast?‖ he gave a conference before the econometric society where he studied

for 45 professional agencies, the ability of selecting stock or of anticipating the

movement of the markets. They do not have better result than the choice made

randomly.

In 1934 holbrook working publishes ―A random difference series for use in the

analysis of time series‖. In the journal of the American statistical Association. He

establishes that there is no correlation between the successive variations of prices

on the markets.

In 1953 Maurice G. Kendall publishes ―the analytics of Economic times series,

Part 1 : in which he demonstrates that the fluctuation of stock prices on the market

is essentially uncertain. This worried many economists for whom the stock prices

changed in order to reflect the modifications in the forces of offer and demand. We

were going towards the emergence of the hypothesis of market efficiency for

which the uncertain nature of price evolution is a typical symbol of good market

behavior.

In 1963 during a meeting of the Econometric society, Clive W.J Granger and

Oskar Mogenstern present the results of their research on the stock market pricing.

They discovered that the short term movements are uncertain but not long term

ones. They also specify that economic cycles were of little or no importance.

In 1965 Paul A Samuelson publishes ―Proof that properly anticipated prices

fluctuate randomly‖ in the magazine industrial management review.

Samuelson explains that if stock were predictable and not uncertain, it would

therefore be possible to take action in order to generate systematic gains. But these

Page 47: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

47

actions made the stocks uncertain. Therefore, the uncertain nature of the stock

markets does not go against the economic forces who to the opposite, work very

well. This is how the market efficiency hypothesis was born which, at first, was

synonym of uncertain markets.

In 1965-1998 in a series of publications, Eugene Fama will become the father of

the market efficiency. But the notion of efficiency covers different aspects and

clarify the debate, james Tobin suggest in 1984 in ―on the efficiency of the

financial system‖, four major forms of efficiency which include, in economics and

finance, the principal meaning of the concept: informational efficiency,

fundamental, total insurance and behavioral efficiency. Informational efficiency is

concerns portfolio management the most.

In 1965 in the journal of Business under the title ―the behavior of stock prices

―Eugene fama publishes his entire doctorate thesis in which he concludes that

stock prices are unpredictable and follow an uncertain market.

In 1970, fama published in the journal of Finance, the beginning of a trilogy

entitled‖ Efficient capital market: A review of the theory and empirical work‖. He

defines informational efficiency as follows: A market is efficient when in each

instant; the prices incorporate all the pertinent and available information. He

suggests three types of informational efficiency: the weak form, semi-strong form

and strong form. He also specifies that the efficiency test includes two problems:

first the cost of the information and the transactions and second the problem of

joint hypothesis.

The joint hypothesis conditions the efficiency tests. We can never know if it is the

market which is inefficient or if it is the model that is false (the model used to

evaluate the financial assets). This hypothesis will seriously annoy the researchers.

Page 48: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

48

In 1991 fama published ―Efficient capital market ii‖ in which he suggests an

evolution for the tests of the three types of efficiency. To replace the test on the

weak form, he suggests foresee ability of returns. For the test on the semi-strong

form, he suggests studying events and for the strong form, he suggests tests on

private information.

In 1998 fama published the third part of the trilogy, in which he concludes that the

market efficiency hypothesis has survived all of the challenges, namely by the

studies on the market anomalies and by behavioral finance.

1-The issue

Burton G Malkiel in his paper ―The Efficient Market Hypothesis and its critics‖

says that: At the outset, it is important to make clear what I mean by the term

―efficiency‖. I will use as a definition of efficient financial markets that they do not

allow investors to earn above-average returns without accepting above-average

risks. A well-known story tells of a finance professor and a student who come

across a $100 bill lying on the ground. As the student stops to pick it up, the

professor says, ―Don‘t bother—if it were really a $100 bill, it wouldn‘t be there.‖

The story well illustrates what financial economists usually mean when they say

markets are efficient. Markets can be efficient in this sense even if they sometimes

make errors in valuation, as was certainly true during the 1999-early 2000 internet

bubble. Markets can be efficient even if many market participants are quite

irrational. Markets can be efficient even if stock prices exhibit greater volatility

than can apparently be explained by fundamentals such as earnings and dividends.

Many of us economists who believe in efficiency do so because we view markets

as amazingly successful devices for reflecting new information rapidly and, for the

most part, accurately. Above all, we believe that financial markets are efficient

Page 49: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

49

because they don‘t allow investors to earn above-average risk-adjusted returns. In

short, we believe that $100 bills are not lying around for the taking, either by the

professional or the amateur investor.

According to him, Benjamin Graham (1965) was correct in suggesting that while

the stock market in the short run may be a voting mechanism, in the long run it is a

weighing mechanism.

Fama said that market efficiency per see is testable. In 1978, Michael Jensen

declared his belief that "there is no other proposition in economics which has more

solid empirical evidence supporting it."

In 1953 Maurice Kendall published a study3 in which he found that stock price

movements followed no discernible pattern, that is, they exhibited no serial

correlation. Prices were as likely to go up as they were to go down on any given

day, irrespective of their movements in the past. These results lead to the question

of what, exactly, influenced stock prices. Past performance obviously did not. In

fact, had this been the case, investors could have made money easily. Simply

building a model to calculate the probable next price movement would have

enabled market participants to gain large profits without (or with reduced) risk.

Page 50: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

50

2-Meaning of efficient market hypothesis

Fama in his classic paper:‖capital market: review of empirical theory‖, define the

efficient market as a market where the security prices ―fully‖ reflect all available

information. According to Malkiel in 1992, a capital market is said to be efficient

if it fully and correctly reflects all relevant information in determining security

prices. Therefore, more formally the market is efficient with respect to some

information set. Moreover efficiency implies that it is impossible to make

economic profits by trading on the basis of the defined information

set.(paper4you.com,2006).

Dyckman and Morse in 1986, state that ―A market is generally defined as efficient

if (1) the price of the security traded in the market act as though they fully reflect

all available information and (2) these prices react instantaneously, or nearly so,

and unbiased fashion to new information‖

As it was said by Malkiel in 1992, if the market is efficient, the company market

value should be an unbiased estimate of the true value. Nevertheless it is important

to stress on the following points:

1-Market efficiency does not require that market price is equal to the true value.

2-There is an equal probability that stocks are over or under valued at any point in

time.

3-And finally, investors should not be able to consistently identify under or

overvalued stocks using any investment strategy.(Damodaran 2006).

Page 51: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

51

Nevertheless it is important to stress that markets are not efficient due to their

nature but they are driven to efficiency by the actions of the investors.(efficient

market hypothesis: myth or reality)

Fama (Jan. 1965: ‗The behavior of stock-market prices‘):

‗…an ―efficient‖ market for securities, that is, a market where, given the available

information, actual prices at every point in time represent very good estimates of

intrinsic values.‘

Fama (Sep.–Oct. 1965: ‗Random walks in stock market prices‘):

‗An ―efficient‖ market is defined as a market where there are large numbers of

rational, profit-maximizers actively competing, with each trying to predict future

market values of individual securities, and where important current information is

almost freely available to all participants.‘

Fama et al. (1969):

‗…an ―efficient‖ market, i.e., a market that adjusts rapidly to new information.‘

Fama (1970):

‗A market in which prices always ―fully reflect‖ available information is called

―efficient.‖‘

Jensen (1978):

‗A market is efficient with respect to information set θt if it is impossible to make

economic profits by trading on the basis of information set θt.‘

[‗By economic profits, we mean the risk adjusted returns net of all costs.‘]

Fama (1991):

‗I take the market efficiency hypothesis to be the simple statement that security

Page 52: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

52

prices fully reflect all available information. A precondition for this strong version

of the hypothesis is that information and trading costs, the costs of getting prices to

reflect information, are always 0 (Grossman and Stiglitz (1980)). A weaker and

economically more sensible version of the efficiency hypothesis says that prices

reflect information to the point where the marginal benefits of acting on

information (the profits to be made) do not exceed marginal costs (Jensen (1978)).‘

Malkiel (1992):

‗A capital market is said to be efficient if it fully and correctly reflects all relevant

information in determining security prices. Formally, the market is said to be

efficient with respect to some information set, φ, if security prices would be

unaffected by revealing that information to all participants. Moreover, efficiency

with respect to an information set, φ, implies that it is impossible to make

economic profits by trading on the basis of φ.‘

Fama (1998):

‗…market efficiency (the hypothesis that prices fully reflect available

information)...‘

‗…the simple market efficiency story; that is, the expected value of abnormal

returns is zero, but chance generates deviations from zero (anomalies) in both

directions.‘

Timmermann and Granger (2004):

‗A market is efficient with respect to the information set, Ωt, search technologies,

St, and forecasting models, Mt, if it is impossible to make economic profits by

trading on the basis of signals produced from a forecasting model in Mt defined

over predictor variables in the information set Ωt and selected using a search

technology in St.‘

Page 53: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

53

B-MARKET CONDITIONS CONSISTENT WITH EFFICIENCY

According to fama there are some conditions that might help or hinder efficient

adjustment of prices to information. These conditions are:

1-A large number of rational, profit-maximizing investors exist, who actively

participate in the market by analyzing, valuing and trading securities. The market

must be competitive meaning no one investor can significantly affect the price of

the security through their own buying or selling.

2-A market in which there are no transaction costs in trading securities

3-A market in which all available information is costlessly available to all market

participants

4-A market in which all participants agree on the implications of current

information for the current price and distributions of future prices of each security.

In such market, the current price of a security obviously ―fully reflect‖ all available

information but a frictionless market in which all information is freely available

and investors agree on its implications is, of course, not descriptive of market met

in practice. Fortunately, these conditions are sufficient for market efficiency but

not necessarily.

A market can be efficient if ―sufficient numbers‖ of investors have ready access to

available information. And disagreement among investors about the implications

of given information does not in itself imply market inefficiency unless there are

investors who can consistently make better evaluations of available information

than are implicit in market prices.

Page 54: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

54

C-TYPES OF EFFICIENCY

Efficiency implies that all resources are being used to the potential. We can have

three types namely:

1-Information efficiency implies that the prices of the security reflect all

information relevant to pricing security. A pricing efficient market implies

efficiency in the processing of information i.e. the prices of capital assets at all

times are based on correct evaluation of all available information.

2-Allocation efficiency relates to the ability of the market to direct capital to the

projects with the highest risk-adjusted returns.

3-Operational efficiency is achieved when transactions completed on a timely

basis, accurately and at low cost.

D-FORMS OF EFFICIENCY

The term efficient market was coined by fama in 1970 and he classified it into

three forms namely:

1-WEAK FORM EFFICIENT MARKET HYPOTHESIS

The weak form theory is also known as ―Random Walk‖ says that the current price

of the stocks already fully reflect all the information that is contained in the

historical sequence of prices. In another words, we can say that the price of the

stock already stands adjusted to all the historical information available about it.

Therefore there is no benefit so as far as forecasting the future is concerned and

technical analysis which the use of the past prices to predict the future price is of

no use.

Page 55: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

55

This theory can be explained by a simple example: a close look at the stock prices

sometimes reveals that days-of-the week effects (stocks prices may tend to rise on

Monday and fall on Friday) and also; "blue Monday on Wall Street" is a saying

that discourages buying on Friday afternoon and Monday morning because of the

weekend effect, the tendency for prices to be higher on the day before and after the

weekend than for the period of the rest of the week.

Another one is the time-of –the year effects(stock prices may tend to rise in

January), and small firm effect (small firm prices may typically rise more than

large firm prices).

Most of the studies agree support the proposition that price changes are random

and past prices change were not useful in forecasting future price changes

particularly after the transaction costs were taken into account. However, there are

some studies which found the predictability of share price changes for example

fama and French 1988, poterba and summers 1988 in developed market but they

did not reach a conclusion about profitable trading rules.

Hudson, Dempsey and Keasy (1994) found that the technical trading rules have

predictive power but not sufficient to enable excess return in UK market.

Similarly, Nicolaas (1997) also conclude that past returns have predictive power in

Australian market but the degree of predictability of the return is not so high.

The weak form efficiency of the market on the emerging countries presents

controversial result. Most the emerging countries suffer from the problem of thin

trading in addition to that in the smaller markets, it is easier for a larger trader to

manipulate the market. Though it is generally believe that the markets in the

emerging countries are less efficient, the empirical evidence does not always

support this thought. There are two types of groups of finding, the first group finds

Page 56: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

56

weak form efficiency in developing and less developed markets are Branes,

1986,(on the Kuala lumpur stock exchange), chan,gup and Pan 1992,(in major

Asian markets); Dicknson and Muragu 1994 (on the Nairobi stock exchange) and

ojah and Karemera 1999,(on the four latin American countries market) despite the

problems of thin trading, on the other hand, the latter group, who evidenced that

the market of developing and less developed markets are not efficient in weak form

are cheung,wong and ho,(1993) on the market of korea and Taiwan in a world

bank study by claessens,Dasgupta and Glen(1995), report significant serial

correlation in equity returns from 19 emerging markets and suggest that stock

prices in emerging ,markets violate weak form; similar findings are reported by

Harvey(1994) for most emerging markets. Nourrendine Kababa (1998) has

examined the behavior of stock price in the Saudi financial market seeking

evidence that for weak form efficiency and find that the market is not weak form

efficient. He explained that the inefficiency might be due to delay in operations

and high transaction cost, thinness of trading and illiquidity in the market Roux

and Gilberson (1978) and Poshakwale S,(1996) find the evidence of non-

randomness stock price behavior and the market inefficiency on the Johannesburg

stock exchange and the Indian market.

Page 57: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

57

Statistical Tests of Independence

According to the hypothesis of efficient markets, security returns over time are

independent of one another. When testing for autocorrelation, the significance of

positive and negative correlation in returns is measured over time. Brown (1979)

claimed that it is naive to assume that capital markets are perfect for all securities.

He argued that there is negative auto correlation in monthly stock returns, and he

also found a link between beta and the level of autocorrelation. However, he

admitted that for certain sub-samples of securities, perfect capital markets are

valid, and the predictions of the CAPM are close to reality.

MacKinlay and Ramaswamy (1988), among others, looked at intra-day arbitrage

trading between the futures and spot for the S&P 500 index. They reported some

differences in autocorrelation between returns on the futures and spot at short

intervals but find that most of this goes away at the daily level. MacKinlay (1988)

found significant serial correlation in weekly stock prices, rejecting the random

walk hypothesis. Their result did not, however, support any other patterns and

would have few implications to market efficiency. Jegadeesh (1990) reported

significant negative monthly autocorrelation. The magnitude of abnormal returns

was greatest in January. Furthermore, Boudoukh, Richardson and Whitelaw (1994)

found that autocorrelation on futures was indistinguishable from zero. They

claimed that reports of the death of market efficiency had been premature and

greatly exaggerated.

Page 58: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

58

Trading Rules

It is not impossible to have trading rules based on price patterns in the stock

markets. Some of the trading rules will be presented in the following section.

Filter Rules

The filter rule is normally stated as ―purchase stock when it rises by X% from the

previous low, and hold it until it declines by Y% from its subsequent high. At this

point, sell the stock short, or hold cash. Fama and Blume (1966) conducted an

extensive list of filter rules tests. Small filters, typically less than 0.5% seemed to

work the best, and no filters larger than 1.5% produced better results than the buy-

and-hold strategy. The average profits were generally small, but over time, they

substantially outperformed buy-and-hold strategies. Nevertheless, when accounting

for transaction costs, which are substantial in such a transaction-intensive strategy,

all the tested filter strategies became unprofitable. Furthermore, even the most

profitable filter rules imply that cash is never idle, to compete with the buy-and-

hold portfolio. This is very difficult in real life, especially for a world without short

selling, although the aid of modern computing powers might have improved the

performance.

Sweeney (1988) reviewed Fama and Blume‘s tests, and commented that for a

sample from 1970 to 1982, some filter rules seemed to work, provided that

floor traders‘ transaction costs were used. However, Sweeney concluded

that the results were very sensitive to the transaction cost assumptions made

as well as biases in closing price listing

Elton and Gruber (1995) commented that Jennergren and Korsvold (1974) found

some evidence of profitable filter rules in the Norwegian and Swedish markets. We

Page 59: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

59

have not succeeded in finding evidence to whether these opportunities still persist,

although one could assume that they are gone now, as the markets have grown

more liquid.

Often, there will be evidence both for and against a theory. A few of the most

serious attacks on market efficiency have come from a few very influential

articles. Elton and Gruber (1995) classified these tests under market

rationality. This is because they belong to a group of seemingly uncorrected

patterns. Under market efficiency, if a pattern is discovered, it should be

traded away. Market rationality deals with patterns that have persisted

through long time periods

Relative Strength Rules

A popular measure of stock performance is relative strength. A general relative

strength rule would measure today‘s stock‘s price pi,t

against its average

price during the past time period pi*. Following the definitions of Levy

(1967), relative strength would be defined as pi,t

/ pi*. A relative strength

strategy would hence imply buying the X% with the highest relative strength

ratio, and invest equal dollar amounts in them. Following this, sell the

securities whose relative strength rank is below a cast-out rank K7

, and use

proceedings to invest in the upper X%.

In his Ph.D. dissertation, described in Jensen and Benington (1969), Levy tested

this strategy on a sample. The results indicated abnormal returns, but lacked

a significance

Page 60: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

60

test and proper risk adjustments. The best results were obtained with X=10%,

K=1608

and X=5%, K=1409

with corresponding returns of 20% and 26.1%,

unadjusted for risk. Buy-and-hold returns were given at 13.4%. Jensen and

Benington (1969) looked thoroughly into this investigation. After adjusting

for risk, the most profitable strategy earned 1.4% on the buy-and-hold

strategy, not including transaction costs. A further inclusion of transaction

costs would make the strategy unprofitable. Furthermore, Jensen and

Benington (1969) claimed that Levy‘s results were attributable to selection

bias, as the same data was used for all filters. They finally added that ex

post, filters could always be designed to fit a given data set.

Page 61: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

61

EARLY MODELS

The fair game model

Bachelier (1900) presented the fair game approach in his dissertation Theory of

Speculation. In his framework, he distinguished between two sets of probabilities.

The first category he called mathematical probability, which is related to a priori

probabilities, as studied in games of chance. The second category consisted of

probabilities dependent of future events. These latter expectations, Bachelier

(1900) argued, are subjective, cannot be observed and should hence not be part of

the price. Hence, basing the prices on the a priori expectation, the prices would be

fair. In other words, the price should reflect the events known to the market, and

not the events that might occur.

Following this definition, the stock market should be based on security returns

having mathematical expectation equal to zero, using today‘s information in the

market. Consequently, all information should be included in the prices at all times.

Trading on insider information, however, violates this principle; hence the price

would be unfair.

Fama (1970), following what Bachelier once started, used a simple fair game

model to present the efficient market hypothesis. Defining the set Ωtas the

information known at time t, pj,t+1

as the price, and rj,t+1

as return of security j at

time t+1, he presented security prices as follows:

E[pj,t+1

| Ωt] = [1+ E(r

j,t+1| Ω

t)]p

j,t

This is the classical fair game model. A fair game is designed so that the players

know their expected gain or loss to playing the game before playing it. The excess

gain Ωt+1

from the return game can be defined as follows:

Ωt+1= rj,t+1-E[rj,t+1| Ωt] (2)

Page 62: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

62

In accordance to Bachelier‘s condition for a game to be fair, the expected excess

gains E[ Ωj,t+1

| Ωt] should be zero. The consequences of this simple statement are

very important to efficient markets. If the market returns follow a fair game model,

then the best return estimate would be the expected return. Hence, there would be

no initiative to speculate, as the markets best estimate would already be reflected in

the prices. This is in harmony with Fama‘s (1970) definitions, as mentioned in

section 2.1. According to these definitions, if returns do not follow a fair game,

then the market is not efficient

Martingale and submartingale model

Let us now consider the price pj,t

of security j at time t. The stochastic process in

the stock prices where

E[pj,t+1

| Ωt] Ω p

j,t (3)

is a martingale, whereas the similar process

E[pj,t+1

| Ωt] Ωp

j,t (4)

is a submartingale. Basically, the submartingale could be considered as a

martingale with an upward drift. This would imply that Cov(rj,t+1

,rj,t

) is positive. As

long as this autocorrelation is included in Ωt, this does not violate the fair game.

We will refer to both as the martingale model, but note that they have some

differences. For the martingale model, we can define xj,t+1

as the excess price

difference, hence

xt+1

= pj,t+1

-E[pj,t+1

| Ωt] (5)

and E[xj,t+1

| Ωt] should be equal to zero. From (1) and (5) it is easy to deduce that if

prices follow a martingale, then returns2

follow the fair game. The opposite is not

necessarily true, however.

Page 63: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

63

Tests conducted on the stock market prices have to a large extent been based on the

martingale model, due to its simplicity and testability features. If expected stock

prices do not follow the martingale model, this would mean that the stocks are, on

average, incorrectly priced, and arbitrage opportunities would exist. Under the

efficient market hypothesis, rational investors would exploit this opportunity until

it is gone, hence forcing the price back to the martingale model.

Random walk

The discussions on stock market behavior started with Kendall‘s (1953) discovery

that returns appear to follow random walks. The probability density function ft[ Ωt]

of the returns (r1,t+1

, r2,t+1

,…, rj,t+1

,…, rn,t+1

) follows a random walk if:

ft[r

1,t+1 , r

2,t+1 ,…, r

j,t+1 ,…, r

n,t+1] = f

t[r

1,t+1 , r

2,t+1 ,…, r

j,t+1,…, r

n,t+1| _

t] (6)

The return of security j in period t+1 is independent of the information available at

time t. Consequently, no good estimate based on today‘s information will explain

the future returns. A random walk requires the fair game. Hence, modifying (1), we

obtain

Et[r

j,t+1| Ω

t] = E

t[r

j,t+1] (7)

The extensions (or rather the restrictions) from the martingale model are numerous,

as the random walk is a stronger assumption than the fair game. Firstly, the random

walk implies that returns are identically and independently distributed (i.i.d).

LeRoy (1989) claimed this would make the random walk hypothesis far too

restrictive to be generated within a reasonably broad class of optimization models,

hence martingale models would be more tractable

Secondly, the random walk requires variance and skewness to be unaffected by

information. Poteba and Summers (1986) reported that even though there is weak

serial correlation in volatility, random volatility shocks will occur, and volatilities

Page 64: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

64

change over time. LeRoy (1989) added to this discussion, arguing that security

prices are known to have variance patterns of quiet and turbulent periods, not in

agreement with the stable variance assumption. Lo and MacKinlay (1988) put the

evidence in direct relation to the random walk hypothesis. Conducting a variance

bounds test, they found significant serial correlation in stock prices. This would

imply a rejection of the random walk hypothesis.

Finally, the random walk has several other implications, such as price-value

correlation, equilibrium when traded (all information is incorporated), and

normality of price changes. Mandelbrot (1963) found that price change

distributions were not normally distributed, and suggested that these fat tails could

be explained by abandoning a finite variance assumption, and using a more fat-

tailed distribution

Schwert and Seguin (1990) claimed that the conditional distribution of security

returns is much more fat-tailed than the normal distribution, and indicated that the

normality assumption might be violated

Page 65: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

65

2-SEMI-STRONG FORM EFFICIENCY OF THE MARKET

The semi-strong form of the market hypothesis suggests that the current price fully

incorporate all publicly available information. Public information includes not only

past price but also data reported in a company‘s financial statements, earnings and

dividend announcements, announced merger plans, the financial situation of

company‘s competitors, expectations regarding macroeconomic factors such as

inflation, interest rate, GDP, unemployment. Sometimes, the public information

does not have to be of a financial nature. For example, for the analysis of

pharmaceutical companies, the relevant public information may include the current

published state of research in pain relieving drugs.

The raison behind the semi-strong is that one should not be able to profit using

something that ‖everybody else knows‖ since the information is public.

Nevertheless, this assumption is far stronger than that of the weak-form. Semi-

strong form efficiency of the markets requires the existence of market analysts who

are not only financial economists able to comprehend implications of financial

information but also macroeconomists, experts adept at understanding processes in

product and input markets. Such skills may be difficult to acquire and it requires a

lot of time and efforts. In addition to that the public information may be relatively

difficult to gather and costly to process.

Some tests on the semi-strong

Quarterly Earnings

Jones and Litzenberger (1970) suggested that trading techniques based on data

from quarterly earnings beat the market and that the market does not adjust

immediately to these types of announcements. This slow adoption to unexpected

Page 66: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

66

statements in the quarterly earnings is not consistent with the theory that security

prices adjust rapidly to the release of public information.

A later study by Jones and Latané (1979) drew approximately the same conclusion

as Jones and Litzenberger. Jones and Latané found that the adjustment to

unexpected earnings, published in for instance quarterly earnings, was relatively

slow, and that it extends beyond the earnings report date.

Predicting Cross-Sectional Returns

The cross-sectional approach is simple. Stocks are ranked, and sorted into

number of (usually five or ten) quantiles. For each of these quantiles, the returns

are regressed against risk, estimated by some model, and the results are

compared across the different sections. Hence the name cross-sectional

returns. Regressions are usually done using an approach defined in Fama

and MacBeth (1973). The goal is to determine if any factors can be used to

explain returns, after the adjustment for risk.

Studies gathered under cross-sectional return predictability and market efficiency

use a diversity of publicly available statistics, such as accounting data, to rank

stocks. Typical ranking criteria are accounting ratios such as Price/Earnings,

Book/Market value and size (market capitalization).

The cross-sectional tests involve a joint hypothesis problem, because they test not

only the EMH, but also the model used to estimate risk. The conclusions from tests

concerning these apparent anomalies have given rise to a discussion on the

adequacy of beta as a risk measure. If beta does not adequately describe risk, this

would have implications to the use of the CAPM, and favor APT models. Fama

(1991) pointed out that correlation observed between fundamental variables and

Page 67: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

67

returns could be consistent with the EMH, provided they were proxies for omitted

risk factors.

Event studies

Event studies examine how the market responds to certain economic events and if

the stock prices adjust rapidly to these events. The type of economic events can be

either company specific or general for the economic or political situation.

3-STRONG FORM EFFICIENCY OF THE MARKET

The strong form efficiency states that the current prices of the security fully

incorporate or reflect all existing information; both public and private (sometimes

called insider information). So not only the public information which is useless to

the investor but all the information. The differences between the semi-strong form

and the strong form efficiency are that in the latter, nobody should be able to

systematically generate profits even if trading on information not publicly known

at the time. In other words, the strong form states that a company‘s management

(insiders) are not able to systematically gain from inside information by buying

company‘s shares ten minutes after they decided(did not publicly announce) to

pursue what they perceive to be very profitable acquisition. Similarly, the members

of the company‘s research department are not able to profit from the information

about the new revolutionary discovery they completed half an hour ago. The

rationale for strong form market efficiency is that the market anticipates in an

unbiased manner, future development and therefore the stock price may have

Page 68: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

68

incorporated the information and evaluated in a much more objective and

informative way than the insiders.

Since the first event studies, numerous papers have demonstrated that early

identification of new information can provide substantial profits. Insiders who

trade on the basis of privileged information can therefore make excess returns,

violating the strong form of the efficient markets hypothesis. Even the earliest

studies by Cowles (1933, 1944), however, make it clear that investment

professionals do not beat the market. While there was evidence on the performance

of security analysts, until the 1960s there was a gap in knowledge about the returns

achieved by professional portfolio managers. With the development of the capital

asset pricing model by Treynor (1961) and Sharpe (1964) it became clear that the

CAPM can provide a benchmark for performance analysis. The first such study

was Treynor's (1965) article in Harvard Business Review on the performance of

mutual funds, closely followed by Sharpe's (1966) rival article. The most

frequently cited article on fund managers' performance was to be the detailed

analysis of115 mutual funds over the period 1955-64 undertaken by Jensen

(1968). On a risk-adjusted basis,he finds that any advantage that the portfolio

managers might have is consumed by fees and expenses. Even if investment

management fees and loads are added back to performance measures, and returns

are measured gross of management expenses (ie, assuming research and other

expenses were obtained free), Jensen concludes that "on average the funds

apparently werenot quite successful enough in their trading activities to recoup

even their brokerage expenses."Fama (1991) summarises a number of subsequent

studies of mutual fund and institutional portfolio managers' performance. Though

some mutual funds have achieved minor abnormal gross returnsbefore expenses,

pension funds have underperformed passive benchmarks on a risk-adjusted basis. It

Page 69: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

69

is important to note that the efficient markets hypothesis does not rule out small

abnormal returns, before fees and expenses. Analysts could therefore still have an

incentive to acquire and act on valuable information, though investors would

expect to receive no more than an average ne return. Grossman and Stiglitz

(1980) formalise this idea, showing that a sensible model of equilibrium must leave

some incentive for security analysis.To make sense, the concept of market

efficiency has to admit the possibility of minor market inefficiencies. The evidence

accumulated during the 1960s and 1970s appeared to be broadly consistent with

this view. While it was clear that markets cannot be completely efficient in the

strong form, there was striking support for the weak and semi-strong forms, and

even for versions of strong form efficiency that focus on the performance on

professional investment managers

Some tests on strong form efficiency

Corporate Insiders

Some of the studies of corporate insiders, like Finnerty (1976), have examined

corporate insiders and tried to determine how well they do relative to the market in

general. Other studies, for example Rozeff and Zaman (1988), examined the

returns for the corporate insiders as well as returns for outsiders basing their

decisions on publicly available information concerning insider trades.

The aspect of trades from corporate insiders has been studied since the 1960s.

Rogoff (1964) concluded in his dissertation that insiders have an advantage over

outsiders when they are trading in their own companies. But he also stated that the

variability of the excess returns was too high to conclude that they had a persistent

advantage compared to speculators

Page 70: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

70

Jaffe (1974) concluded that insiders did possess special information, but that the

excess profits were substantially affected when including transaction costs. He was

also aware of the limitations of his study, caused by the fact that it only contained

trades that had to be reported. Insiders could always leak information to others or

they could trade in companies that were affected by decisions in their own

company.

Finnerty (1976) published a study that investigated insider trades for the New York

Stock Exchange firms during the time period from January 1969 to December

1972. Based on a methodology developed by Jensen (1968), which described the

risk premium of an individual security above the market return, Finnerty (1976)

evaluated both buy and sell portfolios. For the buy portfolios, results were

evaluated for up to 12 months after the trade. The returns were consistently

positive and significantly different from zero. For the sell portfolios, results were

similar, indicating that securities sold by insiders fell more than the market in the

months following the trade. When comparing the post-trade months, the first

month showed the greatest abnormal return. This might have been caused by the

fact that the insiders‘ trades became public information soon after the trade. The

conclusion from this study was that insiders were able to identify profitable or

unprofitable situations in their own company in the short-run. Although his

methodology was somewhat different, Finnerty‘s (1976) results were aligned with

the results of Jaffe (1974), and both studies refuted the strong-form of the efficient

market hypothesis

Rozeff and Zaman (1988) considered both the potential excess returns for

corporate insiders as well as the possibilities for outsiders to make above average

returns based on publicly available information considering insider trades. A

possible above average return based on publicly available information will violate

Page 71: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

71

the semi strong-form of the efficient market hypothesis. This violation is referred

to as the insider-trading anomaly, because it is based on insider trades. Rozeff and

Zaman (1988) also investigated whether positive abnormal returns linked to insider

trades could be explained by other factors such as size or P/E ratios. For the 1973 –

1982 period, an insider-trading anomaly was present. Although the excess returns

for shorter periods disappeared after including transaction costs (2%), the returns

for the 12-month horizon was significantly higher than the market return. When

adjusting the market model for the size and P/E effects, the excess return for the

12-month horizon became insignificant. These results suggested that the abnormal

returns experienced by outside traders, basing their activities on the trades of

corporate insiders, were mainly caused by size and P/E effects. For the insider

trades, the results were positive also after adjusting for both transaction costs and

the size and P/E effects. The study by Rozeff and Zaman (1988) indicated a profit

level of 3.12% per year. Furthermore, they suggested an upper limit of possible

insider trade profits of at most 5% annually.

The suggestion that the size effect is responsible for a great deal of the abnormal

returns is further supported by Gregory et al., 1994). Their findings supported the

conclusion that when you include the size effect, the abnormal returns for insider

trades will become insignificant.

Kara and Denning (1998) based their empirical test of the strong-form efficiency

on insider trades in the period ranging from March 1979 to July 1980. Based on

these data they indicate a rejection of the strong-form hypothesis

Page 72: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

72

Stock Exchange Specialists

Because of the monopolistic access to certain information, one would intuitively

expect that stock exchange specialists are able to earn above-average returns.

Niederhoffer and Osborne (1966) found that specialists' monopolistic power over

information provided an edge for them to earn abnormal returns. A study by the

SEC (Securities and Exchange Commission) in the early 1970s also supported this

belief and contradicted the theory of strong-form efficiency. More recent studies

have showed that abnormal returns for specialists are decreasing

Security Analysts

Security analysts have experience and practice in finding undervalued stocks. The

studies of security analysts will therefore give a more meaningful approach to the

strong-form testing, independent of the possession of some specific position. The

evaluation of security analysts preceded the hypothesis of efficient markets.

Cowles (1933) concluded that neither the 16 financial services nor the 24 financial

publications engaged in forecasting the stock market were able to outperform a

random selection of stocks. Even the best records in each of the groups failed to

present results that were significantly better than random performance. Cowles

continued his study and reached the same conclusion in a later paper (Cowles,

1944). The results indicated that leading financial periodicals and services failed to

successfully predict the future course of the stock market.

Holloway (1981) investigated both buy-and-hold strategies and active trading

based on the Value Line ranking. The buy-and-hold strategy accepted the rank-1

stocks from Value Line at the beginning of the year. The portfolio is held

Page 73: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

73

unchanged for one year and then adjusted based on the ranking for the next year.

This strategy gave abnormal returns even after the adjustment of transaction costs.

The active strategy version of the Value-Line ranking strategy changed the

portfolio consistently when the stocks weekly moved in or out of the rank-1

category. This strategy was able to earn positive abnormal returns without

transaction costs, but the returns were consumed when adjusting for trading.

Holloway (1981) was also taking into consideration whether the results were

explainable by a failure to adjust for risk. His investigation suggested no such

evidence.

Hunerman and Kandel (1990) tried to reconcile the Value Line record with the

efficient market hypothesis. They claimed that their model showed that Value

Line‘s rankings predicted systematic market-wide factors, and that the alleged

abnormal returns from positions based on Value Line were compensation for the

systematic risk associated with these positions.

Womack (1996) presented some evidence on the ability of analysts to predict or

influence stock prices. He evaluated buy and sell recommendations made by

analysts and concluded that they had a substantial impact on both an immediate

and a long-term basis. He claimed that this was consistent with the expanded view

on the efficient market hypothesis suggested by Grossman and Stiglitz (1980).

They advocated that there had to be returns to costs induced by information search.

Page 74: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

74

Chapter 5

TECHNICAL ANALYSIS AND EFFICIENT MARKET HYPOTHESIS

The theory that past prices could be used to guide future investment decisions was

first formalised by Charles Henry Dow (1985-1902), the founder of Wall Street

and Dow Jones Company. His early work gave rise to a number of theories and

techniques which are now employed everywhere by investors in their trading

decisions.

The term technical analysis refers to a myriad of trading techniques. ―Technical

analyst attempt to forecast prices by the study of past prices and a few other related

summary statistics. They believe that shifts in supply and demand can be detected

in charts of market action‖ (Brock et al 1992).

A-PRINCIPLE OF TECHNICAL ANALYSIS

Neely in 1997 describes three principles which guide the behaviour of technical

analysts. The first is that ―market discounts everything‖. In other words, all prices

movement are ―a reflection of the trend in the hopes, fears, knowledge, optimism

and greed‖ [pring, 2002]. As Drew in 1968 noted that the price level is ―never what

they [stocks] are worth, but what people think they are worth‖. As such there is no

need to forecast the fundamental determinants of an asset‘s value. In fact Murphy

in 1986 claimed asset price changes often precede observed changes in

fundamentals.

The second principle states that the ―trend is your friend‖. Technical analysts

maintain that asset prices move in trends and typically do not believe that price

fluctuations are random and unpredictable.

Page 75: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

75

Neely provides an example of what markets may be inclined to trend. First we

assume that there is asymmetric information in the market i.e. some participants

will have more information than others. It is likely that the trading behaviour of

these participants will reveal some of their private information to uninformed

participants. Let us assume that some investors have obtained some information

about the fundamental determinants of a company which is likely to push the price

of the share to go up. They will buy the share of the company which will raise the

price of the share as they purchase more.

When uninformed investors notice this behavior, they also will buy the same share

increasing more the price of the share as they also buy. This is known as self-

fulfilling prophecy. Individuals believe that the share price is going to rise, and

acting upon this belief, will cause the share price to rise independent of other

factors. Therefore, the market is predisposed to trends. Some practionners even

appeal to Newton’ law of motion to explain the existence of trend:‖trends in

motion tend to remain in motion unless acted upon by another force.‖

Predictable trends are essentials to a technical analyst. They are what allow traders

to profits by buying assets when the price is rising and selling when the price is

falling.

The third and final principle is that history repeats itself. The assumption is made

that the emotional make-up of investors will not change. As such asset traders will

tend to react the same way to the same market conditions and therefore, the

subsequent price movements are likely to be similar. ―Technical analysts do not

claim their methods are magical; rather that they take advantage of market

psychology‖[Neely, 1997]. The objective is therefore to uncover signals given off

in a current market by examining past market signals.

Page 76: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

76

Technical analysis employs two main analyses: charting and Mechanical rules.

A-TECHNICAL ANALYSIS TECHNIQUES: CHARTING

Charting involves graphing the history of prices over some period determined by

the analyst to predict future patterns in the data based upon past patterns. This

method is much more subjective than the mechanical technique. It requires the

analyst to use judgment and skills in finding and interpreting patterns. It is the

process of establishing patterns within a series of data by visual inspection. To

identify trends it is first necessary to find the maximum called peaks and the

minimal also called troughs in the data. Peaks and troughs allow us to establish the

uptrend and the downtrend respectively.

Once technicians have identified the trend line, they will trade as necessary as

possible. Buying at one level and selling at another level.

Detecting the reversal of an established trend is just as important as identifying the

trend itself. If a trend reversal is indicated, a trader can profit by reversing hi/her

position. Peak and trough are also used for this purpose. Local peaks are called

resistance levels and the local troughs are called support levels. A price failing to

break a support level during a downtrend is thought to be an early indication that

the trend may soon reverse.

Another useful patterns identified the future movement of price are head and

shoulders which are considered by the technicians are the most reliable of all chart

pattern.

Page 77: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

77

B-TECHNICAL ANALYSIS TECHNIQUES: MECHANICAL RULES

Mechanical trading rule avoids the subjectivity such fear or greed and provides a

consistent and disciplined approach to technical trading. Mechanical rules use

statistical rules in order to obtain buy and sell signals.

We can have three subcategories of mechanical rules namely: Filter rule, Moving

average rules and oscillators.

FILTER RULES

Alexander formulated the filter rules to test the belief held among the

professionals that prices adjust gradually to new information. For him the filter

rules means that ―if the stock price has moved up percent it is likely to move up

more than further before it moves down percent.‖

MOVING AVERAGE RULES

The moving average is a lagging indicator which is easy to construct and it is one

of the most widely used. A moving average, as the name suggests, represent an

average of a certain series of data that moves through times. The most common

way to calculate the moving average is to work from the last 10 days of closing

prices. Each day, the most recent close (day 11) is added to the total and the oldest

close (day 1) is substrated. The new total is then divided by the total number of

days (10) and the resultant average computed. The purpose of the moving average

is to track the progress of a price trend. The moving average is a smoothing device.

By averaging the data, a smoother line is produced, making it easier to view the

underlying trend. A moving average filters out random noise and offers a smoother

perspective of the price action.

Page 78: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

78

OSCILLATORS

Oscillators are used as overbought or oversold indicators. A market is said to be

overbought when prices have been trending higher in a relatively steep fashion for

some time, to the extent that the number of market participants long of the market

significantly outweighs those on the sidelines or holding short positions. This

means that there are fewer participants to jump onto the back of the trend. The

oversold condition is just the opposite. The market has been trending lower for

some time and is running out of fuel for further price declines.

Oscillators indicators move within a range, say between zero and 100, and signal

periods where the security is overbought (near 100) or oversold (near zero).

Oscillators are the most common type of technical indicators. The technical

indicators that are not bound within a range also form buy and sell signals and

display strength or weakness in the market, but they can vary in the way they do

this.

Page 79: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

79

FUNDAMENTAL ANALYSIS STRATEGY FOR PRDICTING THE STOCK

RETURNS

According the efficient market hypothesis, publicly available information cannot

be used to predict returns and systematically generate abnormal profits. According

to fundamental analysis, stock price reflects the firm‘s ability to generate positive

future earnings therefore to earn abnormal returns using historical accounting data,

researchers suggest that financial statements data should inform on firm‘s future

earnings performance.

OU & Penman in 1989, the pioneers in this research area, document the existence

of significant abnormal returns to a trading strategy that is based on the prediction

of the sign of future changes in annual earnings per share (EPS).

Piotroski 2000 provides evidence supporting the predictive ability of historical

accounting signals with respect to future stock price adjustments for a sample of

value stocks characterized by high Book-to-Market value (BM). They remark that

less than 44% of all high BM firms earn positive return. International Research

Journal of Finance and Economics - Issue 30 (2009).

Market-adjusted returns in two years following portfolio formation and suggest

that investors could benefit by discriminating ex-ante between the eventual strong

and weak companies. Using nine fundamental signals relating to three areas of the

firm‘s financial condition: profitability, financial Leverage, liquidity and operating

efficiency, they classify firms in ten portfolios depending on the signals‘

implication for future prices and profitability. Their results show that the mean

returns earned by a high book to market investor can be increased by at least 7, 5%

annually through the selection of financially strong high BM firms. Moreover, an

investment strategy that buys expected winners and shorts expected losers

Page 80: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

80

generates a 23% annual return. Like AB 1997, 1998, their results support the

ability of historical accounting information to predict future firm performance and

the market‘s inability to recognize these predictable patterns.

FUNDAMENTAL SIGNALS

Twelve fundamental signals have been chosen from previous fundamental

research. The selection criteria of these signals have been relied on the predictive

ability with respect to future earnings performance and returns.

Each firm‘s signal realization is classified as either good or bad according to its

expected implication for future earnings and then prices. A binary variable is

created for each signal that is equal to one if the signal‘s realization is good and

zero if it is bad.

1-inventory (INV)

This ratio measures the percentage change in sales relative to the percentage

change in inventory. Inventory increases faster than sales is considered a negative

signal because it suggests difficulties in generating sales or the existence of slow-

moving or obsolete items that will be written off in the future. All these factors

affect negatively future earnings

2-Account Receivable (AR)

This signal represents the percentage change in sales less an analogous measure of

accounts receivable. A disproportionate increase in accounts receivable relative to

sales suggests cash collection difficulties and problems in selling the firm‘s

products. Also, it may likely provoke future earnings decreases as provisions of

future receivables experience an eventual increase. These arguments imply future

Page 81: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

81

earnings decreases. So a positive value to this signal is considered good news. It is

attributed one (zero) to this ratio when it is positive (negative)

3-INVESTMENTS (INVES)

This signal measures the percentage change in capital expenditures relative to the

percentage change in sales 2. A negative value of this ratio is considered bad news

by analysts. In fact, capital expenditures are largely discretionary. So an unusual

decrease is generally suspect. This decrease may indicate managers‘ concerns with

the adequacy of current and future cash flows to sustain the previous investment

level. Moreover, analysts associate this decrease with a short-term managerial

orientation. The binary variable associated to this signal takes the value of one

(zero) if this signal‘s realization is positive

(Negative).

4-GROSS MARGINS (GM)

This signal is defined as the percentage change in gross margin less an analogous

measure for sales. A decrease in gross margin relative to sales is considered bad

news. In fact, it indicates a deterioration of the firm‘s terms of trade or lack of

cost‘s production control. According to Lev & Thiagarajan 1993, variations in this

fundamental signal affect long-term performance of the firm and it is therefore

informative with respect to earnings persistence and firm values

5-LABOUR FORCE (LF)

This ratio is defined as the change in sales per employee. It is used by analysts to

appreciate the effects of restructuring decisions. In fact, decisions of labor force

reductions are generally associated with increases in wage related expenses that

Page 82: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

82

affect negatively current earnings but bode well for future earnings. That‘s why a

similar signal is generally used to better assess future earnings.

6-7- RETURN ON ASSETS (ROA) AND VARIATIO IN RETURN ON ASSETS

(ΔROA).

ROA is defined as net income before extraordinary items scaled by beginning of

the year total assets and ΔROA is defined as the current year‘s ROA less the prior

year‘s ROA.

8-CASH FLOW

This ratio is defined as cash flow scaled by beginning of the year total assets.

Where cash flow = Earnings before extraordinary items – Accruals, And Accruals

are defined as is common in the earnings‘ management literature (Dechow, Sloan

& Sweeney 1995, Sloan 1996):

Accruals = (ΔCA - Δ Cash) - ΔCL – Dep

Where: ΔCA: change in current assets

Δ Cash: change in cash/cash equivalents

ΔCL: change in current liabilities

Dep: depreciation and amortization expense

According to Piotroski 2000, the three preceding signals provide information about

the firm‘s ability to generate funds. Firm that realizes positive earnings or cash

flow is demonstrating a capacity to generate some funds through operating

activities. Similarly, a positive earnings trend is suggestive of an improvement in

the firm‘s underlying ability to generate positive future cash flows. So, the binary

Page 83: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

83

variable associated to each signal equals one if the signal‘s realization is positive

and zero otherwise

9-ACCRUALS (ACC)

This signal is defined as accruals scaled by beginning of the year total assets. This

signal measures earnings persistence. Authors like Sloan [1996], Bradshaw,

Richardson & Sloan [1999] and Collins & Hribar [2000] show that persistence of

current earnings is decreasing in the magnitude of the accruals component of

earnings. That is firms with high accruals are more likely to experience declines in

subsequent earnings performance and others with low accruals are more likely to

experience subsequent earnings increase.

Consistent with the negative relation between accruals and future earnings, I

attribute the value of one to the binary variable if the accruals‘ signal is negative

and zero if it is positive.

10-LEVERAGE:

This signal represents change in the ratio of total long-term debt to average total

assets. Literature review interested on financial leverage‘s impact on firm value

has been controversial. Theoretical studies leaded for example by Harris & Raviv

[1990], Stulz [1990] and Hirshleifer & Thakor [1992] show that leverage is

positively related to firm value. However, Myers & Majluf [1984] and Miller &

Rock [1985] consider that leverage increases can negatively impact firm value.

Page 84: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

84

11-LIQUIDITY (ΔLIQUID)

This signal measures the change in the firm‘s current ratio between the current and

prior year. current ratio is defined as the ratio of current assets to current liabilities

at the fiscal year end. Liquidity increases signals the firm‘s ability to service

current debt obligations. So the binary variable attributed to this signal equals one

if ΔLIQUID is positive and zero if it is negative.

12-ASSETS TURNOVER (ΔTURN)

This signal is defined as the firm‘s current year asset turnover ratio less the prior

year‘s asset turnover ratio. The asset turnover ratio is defined as total sales scaled

by beginning of the year total assets. A positive ratio may imply improvement in

asset‘s use that is less assets generating the same levels of sales, or an increase in

firm‘s sale.

MARKET ANOMALIES

A market anomaly is any event or time period that can be used to produce

abnormal profits on stock markets. Stock market anomalies occur across the world.

They do not correspond with existing equilibrium models, where risk is the only

factor which is likely to cause possible variations in stock market excess returns.

The occurrence of pattern in time series of stock market returns, independent of

time varying risk, would indicate that not all relevant information is captured in

stock prices, which is inconsistent with the efficient market hypothesis. Stock

market anomalies exist in every form of the efficient market hypothesis and can be

classified in different categories, like for example firm anomalies, accounting

Page 85: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

85

anomalies, events anomalies, weather anomalies and calendar anomalies.(levy and

Post 2005)

1-FIRMS ANOMALIES: are consequences of firm-specific characteristics (levy

and post 2005). One well-known firm anomaly is the SIZE EFFECT, which states

that returns on small firms are higher compared to returns on large firms, even after

risk-adjustment. Banz in 1981 discovered this size effect especially for the smallest

firms in his sample based on total market value of NYSE from the period 1936-

1975. Kein in 1883 presented the same conclusion for NYSE and AMEX firms in

the period 1963-1979. The research of Banz in 1981 and Keim in 1983 in relation

to the JANUARY EFFECT, is discussed in the later section. Another firm

anomaly is the effect that firms which are followed by only a few analysts earn

higher returns. This effect is known as NEGLECTED FIRM EFFECT. Arbel,

carvel and srebel in 11983 looked at 510 firms from the NYSE, the AMEX and the

over-the –counter markets and divided them into three groups of institutional

holding (intensively held, moderately held and institutionally neglected) and three

groups of size (small, medium and large). For the period 1971-1980 they found

that the neglected firms earn significantly higher returns than firms intensively held

by institutional investors for both the small and the medium size firms.

2-Accounting anomalies: accounting anomalies relate to stock price movement

after the release of accounting information. An example of an accounting anomaly

is the earning momentum anomaly, which implies that firms with a rising growth

rate of earning are likely to have stocks that outperform the market. Another

accounting anomaly is that if the market-to-book value (M/B) ratio is low, the

stocks are likely to outperform the market.(levy and Post 2005). This phenomenon

Page 86: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

86

is investigated by fama and French In 1992. They divided their total sample of

stocks on the NYSE, AMEX and NASDAQ into ten groups based on M/B ratio

and found that the group with lowest M/B ratio had an average monthly return of

1.65%, while the group with the highest M/B ratio only had an average monthly

return of 0.72%.

3-EVENT ANOMALIES: relate to price movements after an obvious event. This

can be for example the announcement that a firm will be listed on a major stock

exchange. After such an announcement, the price of the stock rises. The

recommendation of an analyst is another example of an event anomaly. Depending

on the type of recommendation, the stock price will rise or fall (levy and post

2005).

4-WEATHER ANOMALIES: relate to price changes during certain weather

conditions. Yuan, Zhen and Zhu in 2006 for example, find a relationship between

stock returns and lunar cycles, looking at stock indices of 48 countries around the

world for the period of January 1973 to July 2001. Their condition is that stock

returns are higher on days around a new moon compared to days around a full

moon. Furthermore, they looked at other explanations for this lunar effect, like

macroeconomic announcements, trading volumes, returns volatility and other

anomalies, but none of them appear to be valid. Another investigation concerning

weather anomalies comes from Saunders in 1993. He explores whether the stock

returns on the Dow-jones industrial average and NYSE/AMEX for the period of

1927-1989 are affected by weather conditions. His results suggest that the weather

does not have significant influence on the stock market returns. This is especially

the case for 100% cloudy days and for sunny days (with 0-20% clouds), where the

mean return for the latter group differs most from the overall mean for all days.

Saunders (1993) states that his results are robust to other anomalies like the

Page 87: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

87

January effect, the weekend effect and the size effect. Cao and Wei (2005)

investigate the possible relationship between stock market returns and temperature.

They test whether lower temperatures lead to higher stock market returns due to

aggression and therefore risk-taking and higher temperatures lead to higher or

lower returns depending whether aggression (which causes risk taking) or apathy

(which causes risk-aversion) dictates. Returns on nine stock market indices around

the world between 1962 and 2001 are used. Overall, Cao and Wei (2005) find that

stock returns are significantly negatively correlated to temperature.

The four categories of stock market anomalies discussed above are not further

captured in this research for several reasons. First, in general, there is considerably

less research on these anomalies compared to calendar anomalies like the January

effect, the day-of-the-week effect, turn-of-the-month effect and Halloween effect

and the theoretical foundation for these anomalies is far from solid.

Besides that, for some of the anomalies, like the weather anomalies, the data are

more difficult to obtain and are beyond the scope of this project.

2.3 Calendar anomalies

If a stock market anomaly depends solely on certain periods in a calendar year, it

refers to a calendar anomaly. The followings are calendar namely the January

effect, the day-of-the-week effect, the turn-of the- month effect and the Halloween

effect.

2.3.1 January effect

The January effect is one of the most well-known anomalies. In 1976, Rozeff and

Kinney reported seasonality in stock returns, using monthly rates of return of the

New York Stock Exchange from 1904-1974. The seasonality that they found was

mainly caused by large returns in January, compared to the remaining months of

Page 88: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

88

the year. In their research they focused on the existence of seasonality, they did not

test possible explanations for it. Later on, others looked for possible explanations

of the January effect. A selection of those articles is described in this section,

categorized by their main Explanation for the January effect.

The size effect

Banz (1981) discovered that risk-adjusted returns are higher for small firms than

for large firms based on total market value by using return data from stocks on the

NYSE from 1936 – 1975. By defining sub-periods of ten years, he found that this

‗size effect‘ is not a linear function, so this does not mean that the returns increase

when firm size decreases. Nevertheless, for the smallest firms in his sample, the

effect is strongest. Keim (1983) also investigated the negative relation between

firm size measured in total market value of equity and abnormal risk-adjusted

returns. With data of firms on the NYSE and AMEX from 1963 – 1979, he defined

different portfolios based on firm size and found that the smaller the firm size, the

more excess return increased. Furthermore, his results showed that this effect is

much stronger for January than for the remaining months of the year. In his further

research, Keim (1983) found that approximately half of the size effect is caused by

January returns and roughly a quarter is caused by the first five trading days of

January. The findings of Banz (1981) and Keim (1983) suggest that the January

effect found by Rozeff and Kinney (1976) should be more pronounced on small

capitalization indices.

4-DAYS-OF –THE-WEEK EFFECT

The day-of-the-week effect comes down to the difference in returns between a

particular trading day a couple of trading days compared to the rest of the trading

week. The weekend effect focuses on Monday and Friday returns, stating that

Page 89: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

89

Monday returns are low and negative and Friday returns are high compared to the

remaining trading days of the week. Extensive research has been done to find

explanations for this anomaly. Here are the most important research that was made

in the last few decades regarding the day-of-the week effect and the weekend

effect.

Cross (1973) was one of the first to report differences in returns on Fridays and

Mondays compared to the rest of the week. With daily return data from 1953 –

1970 on the S&P 500, he found a statistically significant difference between Friday

and Monday returns for almost every year in the sample period in both mean

returns and in percentage of time that the index rose on that day. Moreover, his

results showed that Monday indices following a decline on Friday rose in

approximately 24% of the cases, which is significantly different from the reaction

of the remaining trading days of the week following a decline of the previous

trading day. Subsequent to Roll (1973), French (1980) reported that Monday

returns were negative and lower than returns for other days in the week, using daily

returns from the S&P 500 composite portfolio for the period 1953 – 1977. In his

research, he examined if this is the consequence of the weekend prior to each

Monday or the consequence of every non-trading day (Holiday). His results

illustrated that the return on every weekday on its own (with the exception of

(Tuesday) is higher when the day follows a holiday compared to when the day

follows a trading day.

This is different for Tuesday, because Tuesday is the first trading day after the

weekend when Monday is a holiday. Therefore, French (1980) concluded that the

negative Monday returns are caused by a weekend effect.

Cross (1973) and French (1980) did not look for possible explanations for the

weekend effect, although other authors did. Below a selection is given of the

articles of those authors and their findings regarding the weekend effect.

Page 90: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

90

Settlement period

By using mean returns and variances for the S&P 500 and the CRSP value- and

equally-weighted portfolios from July 1962 – December 1978, Gibbons and Hess

(1981) also found negative Monday returns, although no Monday effect in

variances. Moreover, they searched for possible explanations for the Monday

effect. The settlement period explains the more negative Monday returns before

1968 compared to the returns after 1968, because the settlement period was four

business days before February 1968 and five business days after February.

Nonetheless, it does not explain the negative Monday returns from February 1968

– December 1978. Apart from that, the settlement period is nowadays three

business days for stocks.

Release of information

French and Roll (1986) investigated the return variances of weekdays, weekends,

holidays and holiday weekends by means of daily returns on the New York and

American Stock Exchanges from 1963 –1982. They found that the returns are more

volatile during exchange trading hours compared to non trading hours. The three

possible explanations that were given for this are that public information (Which

causes the volatility) is announced more frequently during business days

(weekdays), private information probably influences prices more when the stock

markets are open and the process of trading itself causes volatility. French and Roll

(1986) concluded that their results showed that only a small part of the difference

in variances between trading hours and non-trading hours is caused by mispricing

occurring during trading. The reason for this mainly lies in the difference in

quantity of information announced between trading hours and non-trading hours.

Page 91: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

91

The days-of-the-week effect internationally

Jaffe and Westerfield (1985) contributed to the literature by investigating the day-

of-the-week effect internationally. In all countries in their research, namely the

U.K., Japan, Canada and Australia, they found a day-of the-week effect with

significant negative Monday returns and high Friday returns.

Correlations tests suggest that there is a strong correlation between the returns of

the four foreign countries and those of the U.S. Nonetheless, independent of the

day-of-the-week effect in the U.S. Jaffe and Westerfield (1985) found a day-of-the-

week effect in each of the four countries on their own. Similar to Gibbons and

Hess (1981), they looked at settlement periods to explain the day-of-the-week

effect. They only found little evidence for the higher Thursday and Friday returns

in Australia, but for Canada, the U.K. and Japan the settlement period did not

explain the day-of-the-week effect at all. In addition, Jaffe and Westerfield (1985)

investigate the opportunity that measurement errors cause the day-of-the-week

effect. They state that if Monday returns would be influenced by mainly negative

random errors and Friday returns by mainly positive random errors, the correlation

between Monday and Friday returns should be low. Nonetheless, they found a

higher than average correlation between Monday and Friday returns and therefore

conclude that measurement errors cannot explain the day-of the-week effect.

In their exploration of different anomalies on stock market indices in eighteen

countries across the world, Agrawal and Tandon (1994) captured the day-of-the

week effect as well. They found negative returns on Mondays for thirteen countries

(of which seven are statistically significant), but also negative returns on Tuesdays

in twelve countries (of which eight are statistically significant). Furthermore, they

found Tuesday returns to be lower compared to Monday returns in eight countries.

Contrary to these negative Monday and Tuesday returns, they revealed positive

Wednesday and Friday returns in the majority of the countries. After reporting the

Page 92: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

92

day by day returns, Agrawal and Tandon (1994) discussed possible explanations

for the negative Tuesday returns. They stated that the time zone hypothesis (which

argues that Tuesday returns are low in some countries due to time-differences that

exceed twelve hours) can explain the negative Tuesday returns in three of the five

countries, but cannot explain the negative Tuesday returns in European countries.

Furthermore, the difference between trading days and non-trading days is not an

explanation for the negative Tuesday returns. After running day-of-the-week

correlation tests and regressions, the null hypothesis that day by day variances are

dependent on the US can be rejected for the majority of the countries. Moreover,

Agrawal and Tandon (1994) argued that the settlement procedure explains a part of

the day-by-day differences (mainly the higher returns on Wednesday, Thursday

and Friday) in returns, but cannot explain the negative Monday and Tuesday

returns for most of the countries. Furthermore, they divided their total sample

period into two sub-periods and found that in the seventies Monday returns are

significantly negative in seven countries and Tuesday returns are significantly

negative in nine countries, while in the eighties the Monday and Tuesday returns

are not significantly negative in the majority of the countries. Finally, they found

that Monday returns are negative in almost all countries if the market declined the

previous week, but mainly positive when the market went up the previous week.

However, this is not found for Tuesday returns.

4-TURN-OF-THE-MONTH EFFECT

The turn-of-the-month effect refers to higher stock market returns for the trading

days surrounding the turn of the month compared to the remaining days of the

month. In the past decades, many researchers discussed the turn-of-the-month

effect, all with their own approach. By looking at the stock returns of the CRSP

Page 93: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

93

value-weighted and equally-weighted index for the period (1963 – 1981, Ariël

(1987) concluded that the mean cumulative return of the first half of trading

months is significantly higher than the mean cumulative return of the second half

of trading months. For this, he added the last trading day of the month to the first

half of the following month. In the entire period he examined, the mean return of

the first half of the month was positive and the mean return of the last half of the

month was equal to zero. At five percent significance level, he did not find

unequal variances between the first half of trading months and the last half of

trading months. This effect is not induced by outliers either. After reporting this

effect, Ariël (1987) looked for possible causes of the difference in mean returns

between the two periods. He reported that the effect is not caused by a

concentration of dividend payments, holidays or weekends in the first or last half

of the month. Furthermore, the effect still held after correcting for returns in

January and therefore was not caused by the January effect. Moreover, the effect is

not induced by a few months where the effect is strongest.

5-halloween effect

The Halloween effect refers to lower stock returns during the period May –

October compared to the returns during November – April. It was first presented

by Bouman and Jacobsen (2002). They concluded, using monthly stock returns of

value-weighted market indices of 37 countries for the period January 1970 –

August 1998 that the Halloween effect is present in 36 countries and is particularly

economically significant in many European countries. After using the regression

technique, Bouman and Jacobsen (2002) concluded that there is a statistically

significant Halloween effect at 10-percent level in 20 of the 37 countries. These

Page 94: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

94

results, they said, are also robust over time. Besides finding the Halloween effect

in their sample, they looked for possible explanations for it.

After running different tests, they rejected data mining, difference in risk, the

January effect, differences in interest rates and trading volumes as possible

explanations. Furthermore, they did not find any seasonal effect in the news which

could explain the Halloween effect. While Bouman and Jacobsen (2002) did not

find an explanation for the Halloween effect; other articles did present possible

explanations.

BEHAVIORAL FINANCE AND EFFICIENT MARKET HYPOTHESIS

The behavioral finance is a new area of financial research that explores the

psychological factors affecting investment decisions. It attempts to explain market

anomalies and other market activity that is not explained by the efficient market

hypothesis.

The fundamental basis of behavioral finance is that psychological factors, or

behavioral biases, affect investors, which limits and distorts their information and

may cause them to reach incorrect conclusions even if the information is correct.

Behavioral Biases

Behavioral biases can be categorized in many ways, and many of these categories

may be overlapping or indistinguishable. The following factors have been

published as having some impact on the market. Contrarian and momentum

strategies take advantage of some of these psychological factors.

Page 95: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

95

Emotional Factors

Emotion often overrules intelligence in decisions and can filter facts, where the

investor may give too much weight to facts that are agreeable and may tend to

ignore or underweight facts that are antithetical to one's predisposition.

There is the fear of regret, or regret avoidance, which causes investors to hold

losing positions too long in the hope that they will become profitable or sell

winners too soon to lock in profits lest they turn into losses.

Overconfidence in one's abilities can lead to higher portfolio turnover and to lower

returns. Despite the fact that few investors or even professional portfolio managers

beat the market over an extended time, there is still a considerable amount of active

portfolio management. One study has shown, on the average, that men have lower

returns than women because they trade more actively, presumably because they

have greater confidence in their abilities.

Conservatism is the hesitation of many investors to act on new information, where

such information should dictate an action or a change to one's strategy. This

hesitation to news, for instance, eventually leads to action at different times for

different investors, leading to momentum as more investors start reacting to the

news.

Belief perseverance is the persistence of one's selection process and investment

strategies even when such strategies are failing or are suboptimal, causing the

investors to ignore new information that may contradict one's decisions.

Loss aversion is the propensity for people to avoid losses even for possible gains.

Hence, people often hang onto losing stocks longer than they should, since selling

Page 96: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

96

would actualize the loss; otherwise, it is still just a "paper loss". Loss aversion is

related to the marginal utility of money, where the 1st dollars are more valuable

than additional dollars. For instance, most investors would avoid an investment

where there was a 50% chance of either earning $50,000 on a $100,000

investment, or an equal chance of losing the same amount, because the $50,000

lost would have greater marginal utility, and therefore be more valuable to the

investor, than the $50,000 potentially gained.

Misinformation and Thinking Errors

Misinformation and thinking errors probably account for most market

inefficiencies, since no one knows everything and, even if they did, they may not

make the best decisions based on that information.

Forecasting errors are a typical example, since even stock analysts are frequently

wrong about future earnings and prospects for the companies that they cover.

Representativeness is the extrapolation of future results based on a limited set of

observations or facts; hence, this is sometimes known as small sample neglect.

This is best illustrated by investors seeking a fund in which to invest, and basing

their decision on the fund's most recent performance rather than covering a longer

period of time, especially during bear markets. Often, this is the result of the lack

of due diligence, where the investor relies on brochures or other advertising

materials put out by the company or fund instead of doing independent research.

Narrow framing is the evaluation of few factors that may affect an investment. For

instance, an investor may buy a security because of its past performance without

considering economic factors that may be changing that could change the

performance of the security. Mental accounting is a specific kind of narrow

Page 97: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

97

framing in which different investments are mentally segregated, applying different

criteria and due diligence to different investments where the different consideration

may be unwarranted. For example, treating separate investments as if they were the

only investment rather than as part of one's portfolio.

Biased information gathering and thinking is the distortion of personal bias on

facts and thinking to conform with one's current opinions or actions.

Limits to Arbitrage

So if behavioral bias misprices stocks, why don't arbitrageurs take advantage of the

mispricing, by buying and selling until the mispriced stocks are equal to their

intrinsic value? Behavioral advocates have argued that mispricing persists because

there are limits to arbitrage.

First, there is the risk that the mispricing will get worse, and, therefore, present a

risk to arbitraging. The market influence of behavioral bias may be greater than the

influence of arbitrageurs, especially since arbitraging behavioral bias is not risk-

free. And even if prices do trend toward their intrinsic prices, it may take longer

than arbitrageurs think—maybe longer than their investment horizon.

Secondly, financial models may be inaccurate, making arbitrage risky.

Thirdly, much of the arbitrage activity would require short selling, which, with

stocks, is very risky, and many institutional investors are not permitted to sell

short.

Page 98: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

98

Herding Behavior

An explanation for momentum strategies is called herding behavior. Banerjee

(1992) defined herding as doing what everybody else is doing, even when evidence

(i.e. private information) implied it might be cleverer not to. His theory was

supported by the momentum patterns discovered in the empirical research of

Jegadeesh and Titman (1993). Grinblatt, Titman and Wermers (1995) investigated

mutual fund behavior, finding that funds did have a tendency of buying past

winners, and, more specifically, engaged in herding. The evidence was not,

however, particularly strong. Since institutional holdings comprise a large

percentage of total equity holdings, at least in the US, this is, at least partially,

compelling evidence for a momentum factor. Herding behavior, as described,

should result in intermediate term momentum, and a long-term reversal pattern,

and its effects are hence, very similar to the theories of noise trading.

Why do people engage in herding? As commented in section 6.2.1, fund managers

might engage in window dressing to take care of agency problems. Furthermore,

tax-loss selling might explain some of the herding behavior. Herding is not,

however, consistent with Markowitz-rationality.

As already mentioned, Black (1986) claimed that true value is not observable.

Hence, it would be difficult to measure whether a stock price really is in

equilibrium. A direct test of herding might therefore be difficult to design.

However, the momentum effects of Jegadeesh and Titman (1993) could be

interpreted as evidence supporting crowd Of course, true fundamental value is not

known (Black 1986).

As already mentioned, Black (1986) claimed that true value is not observable.

Hence, it would be difficult to measure whether a stock price really is in

Page 99: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

99

equilibrium. A direct test of herding might therefore be difficult to design.

However, the momentum effects of Jegadeesh and Titman (1993) could be

interpreted as evidence supporting crowd

overreaction. Furthermore, DeBondt and Thaler‘s (1985) results on long-term

reversals might also indicate that there has been an overreaction. In retrospect,

however, it is easy to use herding to explain under- and over-reactions. The counter

argument could be that the theory was fitted to explain empirical results, hence

indicating a data-mining bias. The persistence of the effect is one of the serious

challenges to the EMH.

Page 100: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

100

Chapter 6

DATA AND RESEARCH METHODOLOGY

The monthly price indices are examined for the empirical analysis from Ghana

stock market for a period of two years starting January 2007 to December 2008.

The whole sample includes 24 monthly observations. This sample takes in account

all the trading days except the holidays and the weekends.

Some information was collected through direct interview and questionnaires with

brokerage houses which are buying and selling in the Ghana stock market.

Other information was collected through direct interview with the research

department of the Ghana stock exchange and through reading materials in the

library of the Ghana stock exchange.

RESEARCH METHODOLOGY

This paper investigates the weak form efficiency of the Ghana stock market by

employing a statistical test or regression test. Indeed, the hypothesis that stock

market price index follow a random walk is tested. Accordingly to the null and

alternative hypotheses for weak form efficiency test are:

Ho = Ghana stock market‘s price indices are weak form efficient

H1 = Ghana stock market‘s price indices are not weak efficient or are inefficient

Page 101: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

101

TABLE 1

Data

MONTH NUMBE

R

GSE ALL

SHARE

INDEX

JANUARY 1 5012.16 MEAN 7559.5762

5

FEBRUAR

Y

2 5044.89 MEDIAN 6664.385

MARCH 3 5092.25 STD

DEVN

2368.7738

92

APRIL 4 5139.65 MAX 10890.8

MAY 5 5224.47 MIN 5012.16

JUNE 6 5294.58 SKEW 0.3708870

63

JULY 7 5341.76 KURTOS

IS

-

1.7249105

55

AUGUST 8 5557.38

SEPTEMB

ER

9 5676.77

OCTOBER 10 5839.62

NOVEMBE

R

11 6387.16

DECEMBE 12 6599.77

Page 102: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

102

R

JANUARY 13 6729.00

FEBRUAR

Y

14 7005.29

MARCH 15 7848.14

APRIL 16 9349.59

MAY 17 9815.22

JUNE 18 10346.3

JULY 19 10650.72

AUGUST 20 10790.95

SEPTEMB

ER

21 10890.8

OCTOBER 22 10788.29

NOVEMBE

R

23 10573.43

DECEMBE

R

24 10431.64

Page 103: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

103

REGRESSION

1-THE REGRESSION ANALYSIS

Regression analysis is a statistical tool for the investigation of relationship between

variables. Usually the investigator seeks to ascertain the causal effect of on

variable upon another. The investigator also assesses the statistical significance of

the estimated relationships, that is, the degree of confidence that the true

relationship is close to the estimated relationship.

Steps in regression analysis:

1-State the hypothesis

If there is a significant relationship between the variables, the slope will not be

zero

Ho: B1 = 0

Ha: B1≠ 0

The null hypothesis states that the slope is equal to zero and the alternative

hypothesis states that the slope is not equal to zero.

2-Formulate an analysis plan

The analysis plan describes how to use the sample data to accept or reject the null

hypothesis. The plan should specify the following elements.

a- Significance level. Often researchers choose significance levels equal to

0.01, 0.05 or 0.10, but any value between 0 and 1 can be used.

b- Test method. Use a linear regression t-test to determine whether the slope of

the regression line differs significantly from zero.

Page 104: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

104

3-Analyze sample data

Using the sample data, find the standard error of the slope, the slope of the

regression line, the degrees of freedom, the test statistics, and the p-value

associated with the test statistic.

a- Standard error. It could be referred to as the standard deviation

b- Slope. Like the standard error, the slope of the regression line will be

provided.

c- Degrees of freedom. The degrees of freedom(DF) is equal to:

DF = n – 2

Where n is the number of observations in the sample.

d- Test statistic. The test statistic is a t-test (t) defined by the following

equation.

t = b1 / stdev

Where b1 is the slope of the sample regression line, and the stdv is the standard

deviation of the slope

e- P-value. The p-value is the probability of observing a sample statistics as

extreme as the test statistics. Since the test statistic is a t-test, use in the

t-distribution to assess the probability associated with the test statistic. Use

the degrees of freedom to compute above

4-Interpret result if the sample findings are unlikely, given the null hypothesis, the

researcher rejects the null hypothesis. Typically, this involves comparing the p-

value to the significance level, and rejecting the null hypothesis when the p-value

is less than the significance level

Page 105: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

105

Table 2

REGRESSION TABLES

Regression

Statistics

Multiple R 0.948715909

R Square 0.900061876

Adjusted R

Square

0.895519234

Standard Error 765.6702638

Observations 24

Page 106: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

106

Table 3

ANOVA table

ANOVA

df SS MS F Significance

F

Regression 1 116157543.3 116157543.3 198.1362124 1.75272E-

12

Residual 22 12897520.96 586250.9529

Total 23 129055064.3

Page 107: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

107

Table 4

INTERPRET REGRESSION COEFFICIENT TABLE

Coefficients Standard

Error

t Stat P-value Lower 95% Upper

95%

Lower

95.0%

Upper

95.0%

Intercept 3586.885109 322.6155376 11.11814123 1.69684E-10 2917.821437 4255.949 2917.821 4255.949

X Variable 1 317.8152913 22.57838429 14.07608654 1.75272E-12 270.9905884 364.64 270.9906 364.64

Page 108: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

108

Testing the significance or efficiency

Hypothesis

Ho : r = 0 (There is no correlation between the prices or )

Ha : r ≠ 0 (There is correlation between the prices)

Where : r = 0.900061876

n = 24

t =

t = 9.688002

Degree of freedom (Df) = n-2 =24-2= 22. This is because of two tailed test.

Using a significance level (α) of 5%. Therefore the t critical from a t-table is listed

below:

t α,(n-2) = t 0.05,(24-2) = t0.05,22 = 1.717

T = 9.688002 and the DF = n-2 = 24-2 = 22

Page 109: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

109

α = 0.05 and the value in the table is 1.717

RESULTS

The test of regression was performed on two years trading result from the Ghana

stock exchange all-share index to determine whether the market is weak form

efficient or to see whether the prices can be predicted. The t-test statistic for the

slope was significant at 0.05 critical level. The t (24) = 9.688 and the p = 1.717.

Thus we reject the null hypothesis and conclude that the market is inefficient

which means that the prices can be significantly predicted. Also if the value of the

test statistic is greater than 1.717 or less than – 1.717, we reject the null hypothesis

(Ho), that there is no correlation and we accept the alternative hypothesis that the

correlation is significant which means that the prices are predictable and the

market is inefficient in short term. From the result, it concludes that the regression

coefficient is significant; this also indicates that the market is inefficient and the

market is predictable from the above result with margins of error.

Page 110: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

110

REASONS BEHIND INEFFICIENCY

One of the main purpose of the main inefficiency in the Ghana stock market is that

most of the investors are not educated enough concerning the pattern of the

market, meaning investors lack adequate knowledge to verify quality shares based

on fundamentals analysis and consequently carrying the transaction or trading

based on speculation or rumor only. The flow of information is not asymmetric to

all the investors at a time resulting into an advantage to a group of investors

acquiring the information early ahead to make abnormal profit.

Another issue is the inequality between the demand and the supply of shares in the

market. First lack of quality shares instigates instability in the market. Second

reason could be the approval of 0% income tax on capital gain encourages

investors to invest in the market which increases the demand where as the supply

remains the same.

Another reason could be the volume of shares traded in the market and also the

size of the market. In addition to the small number of participants and products in

the market, there is also lack of adequate research to improve the efficiency of the

stock market.

There is lack of professionalism in the part of the brokers some of which are only

graduated from the Ghana stock exchange.

Page 111: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

111

SOLUTIONS FOR THE MARKET EFFICIENCY

In order to make the market efficient, investors must believe that the market is

inefficient and that it is possible to outperform it or beat the market. Ironically,

investment strategies intended to take advantages of the market inefficiency are the

fuel that keep the market efficient.

The market must be large and liquid and must also have large number of

participants.

In addition to that the information must be available to all the investors in the

market.

Plus the transaction cost must be cheap as compared to the expected returns and

investors must have enough funds at their disposal.

Page 112: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

112

Chapter 7

CONCLUSION AND RECOMMENDATIONS

CONCLUSION

Referring to the test that has been conducted, it is concluded that the Ghana stock

exchange is not efficient at its weak form. Therefore there is a need to take actions

to improve the efficiency of the market. First, it is important to ensure symmetric

information among all the investors. In addition to the existing awareness creation

policy it is also important to improve on continuous basis to enlighten the investors

about market structure, trading pattern, financial analysis of the listed companies.

Proper implications of the rules of regulatory commission are also needed to be

ensured so that there will not be any scope to violate the market structure to gain

abnormal profit. It is also important that the regulatory commission enforces

policies to ensure improved quality of the stock market. Finally to make more

efficient it is expected that the authority of the market would introduce

sophisticated means of investment and tools in the near future and above all the

campaigns to sensitize people about the importance of the stock market and how to

invest in the stock market and what are the benefits.

Page 113: Efficiency Hypothesis of the Stock Exchange Project Presented by MR CAMARA MOHAMED BINTOU

113

RECOMMENDATION FOR FURTHER RESEARCH

As a result of the inefficiency of the Ghana stock exchange, the following points

should be considered for future research.

1-The Ghana stock exchange should be opened to foreign investors.

2-The foreign investors holding in the GSE should be increased

3-Improve on the clearing and settlement system

4-Improve on the volume traded and participants on the market through the listing

requirement.

5-Campaign to sensitize investors about the importance of the stock market.

6-improve professionalism on the part of the brokers through organizing training

7-Strategies to improve the role of information to make the make efficient

8-High cost of listing on the stock exchange

9-Small float of shares

10-Non-performing companies

11-Impact of the macroeconomic variables