1. Introduction:
For estimating the expected returns on assets, the term used known as Capital Asset Pricing Model (NASDAQ:CAMP). In fact, it is used to assess a firm's expected returns on stock, for merger and acquisition analysis, for capital budgeting and the evaluation of warrants and convertible securities (Thomas, Naylor and Tapon, 1982, pp.1166).
Everyone is abiding the same risk in unusual amounts under the CAPM model. As unsystematic risk can be ignored or has been removed because of this, the investors seize varied portfolio and they will oblige a return for the systematic risk of their portfolios. According to a useful function, an investor will then position portfolios which depend on this portfolio's expected return. It is normal that each one is exactly happy to buy the "market" portfolio as each person grips the identical portfolio of risky assets. In addition, it is likely to diversify element of the risk through the acquirer of many different assets (Bassetto, 2002, p.1).
In 1960s, the model called CAPM was developed by Jack Treynor (1962), William Sharpe (1964), John Linter (1965a, b) and Jan Mossin (1966), but interestingly only William Sharpe received a Nobel Prize for this work in 1990 (Sullivan, 2006).
The purpose of the study is to critically analyze the uses of CAPM, the use of systematic over unsystematic risk in choosing securities, underpriced v/s overpriced securities, assumptions of CAPM, then look at the success of CAPM. At the end it will discuss the rise of Arbitrage Pricing Theory.
2. Definition and Formula of CAPM:
The affiliation between the risk and the expected return on an investment that is used to find out an investment's suitable price is called Capital Asset Pricing Model (CAPM) (Financial Dictionary)."E(ri) = rf+ βi(E(rm)  rf)"
§ ri = Required Rate of Return § βi = Beta of the security § rf = Risk Free Rate § rm = Expected Market ReturnFor example, The Company XYZ, has a beta of 1.7, whereas, the expected market return is 12.5% and risk free rate is 5%. Bear in mind that putting money in company XYZ (βi =1.7) is more risky as compared to investing in the whole stock market where βi = 1.
E(ri) = rf+ βi(E(rm)  rf)
E(ri) = 5% + 1.7 ( 12.5%  5%)
E(ri) = 5% + 1.7 ( 7.5%)
E(ri) = 5% + 12.75%
E(ri) = 17.75%
So, you should get 17.75% return from investing in Company XYZ. If you believe that Company XYZ cannot make these types of returns, in that case it's better to invest in different stocks (TeachMeFinance).
3. Uses of CAPM:
CAPM has many uses; some of them are mention below:
3.1. Security Comparison: On different securities to contrast the rate of return, Investors used CAPM. For example: investment funds, equities, stocks and bonds. A firm can invest intelligently in a portfolio by comparing wisely that reduces the risk and maximizes the rate of return whilst.
3.2. Portfolio and Asset Pricing: The other use of CAPM is to value a portfolio or an investment. In a portfolio, assets can be bonds, real estate, warrants, options, stocks, gold certificates or any related thing that is likely to uphold its worth.
CAPM is also used by modern portfolio theory (MPT) to choose suitable investments for a portfolio. It is a possible contender for enclosure in the portfolio, if the investment is being sold for less than the calculated price (Gilani, n.d.).
3.3. Intrinsic Value: To find out the intrinsic value is a challenge with securities. Asset pricing is the quietest use of CAPM. Investors and analyst use it to evaluate adjacent to the book value and market value stock. Asset is considered as a good deal if it is trading lower than its intrinsic value.
3.4. NPV: For all projects, CAPM uses one discount rate that is why it considers higher in quality to NPV. Therefore, to judge investment projects of all diverse kinds of risk CAPM is used frequently (Bryant, n.d.).
4. Assumptions for Capital Asset Pricing Model (CAPM):
CAPM is based on certain assumptions which are following below:
1. Investors are coherent and risk averse. They follow curiosity of maximizing the expected function of their end of period wealth. Thus if the risk is higher of a portfolio then expected return will be higher.
2. Marketplace is ideal, therefore short selling restrictions, transaction costs, inflation and taxes are not taken into account.
3. Financier can lend or borrow unrestrained amounts at the risk free rate.
4. Every single possession is substantially dividable and entirely liquid.
5. Investors have the same opinion about variance and mean as the only structure of market evaluation, therefore every person perceives the same prospect. And all investors get the same information concurrently.
6. Asset returns obey the rules to the standard allocation.
7. The markets are in symmetry, so the cost of security cannot be influenced by any entity.
8. Quantities and the entire number of assets on the market are predetermined within the defined framework.
Hence in real world, these assumptions cannot be promising but still in security market it has broad functions, therefore it is very significant theory in so far as stock markets are concerned (Parikh, 2009).
5. Systematic Over Unsystematic Risk:
5.1. Systematic Risk: It is also known as "market risk", and it can be defined as uncertainty intrinsic to the whole marketplace or complete market division. Such as recession, global slowdown etc., also referred to as unpredictability, systematic risk consists of the daily variations in a stock's price.
· It is expected to have systematic risk proportionately greater than the risk of the Economy, if an entity's beta is greater than 1. Conversely if an entity's beta is less than 1, it is expected to less than the risk of the economy. However, beta is calculated on the basis of experiences and historic information (Management Accountancy, 2010).
5.2. Unsystematic Risk: Also called the "residual risk" or "diversifiable risk". The risk that is unique to a company such as a natural disaster, the outcome of unfavorable lawsuit, or strike that can be reduced through diversification (Nasdaq).
· Invest in a portfolio of stocks through mutual funds instead of buying individual stocks is the easiest way to diversify unsystematic risk. Mutual funds are fundamentally a basket of bonds, individual stocks or other investment assets. The diagram below clearly shows that adding more stocks to portfolio can decreases unsystematic risk (Young Investors).

6. Importance of the Security Market Line in determining Expected Returns:
The Security Market Line (SML) can be defined as a graphical illustration of the CAPM and it can be describe with respect to its beta, market risk.
'At ßi = 0 the line will intersect the yaxis at the risk free rate. At ßi = 1 the line will be at E(rm) on the yaxis since Cov(rm, rm) / s2m = 1. Also, it can be exposed that the slope of the Security Market Line is equal to the expected excess returns to the market (E(rM)  rf)' (Taylor, 2005).

For example: The beta of Company 'A' is 0.6 and beta for Company 'B' is 1.8. Whereas, 2% is the risk free rate and the required market return is around 5%.
Company 'A' E(ri) = rf+ βi(E(rm)  rf) E(ri) = 2% + 0.6( 5%  2%) E(ri) = 3.8% 
Company 'B' E(ri) = rf+ βi(E(rm)  rf) E(ri) = 2% + 1.8( 5%  2%) E(ri) = 7.4% 
In above scenario, Company 'A' is best option to invest because the required return is greater than the Company B's return. Investing in Company 'B' means that the return we would earn is not sufficient to reimburse us for the risk we are taking (Wall Street Oasis). The investment decision can be taken by plotting an asset, and then investor can decide either asset is under or overpriced (Economic.fundamentalfinance).
7. Overpriced v/s Underpriced securities:
7.1. Underpriced Securities: Assets above the security market line (SML) are considered as underpriced comparative to the CAPM, because the pricing of a new security issue at less than the existing price of the same security in the secondary market. Underpricing helps guarantee a successful sale.
· When the investors become conscious that a security is underpriced they acquire the security for the reason to raising its price. The cost of the security will increase until the security is forced downwards and it sits on the security market line (SML) (weallsomwhere, 2010).
7.2. Overpriced Securities: An overpriced security is a security that provides an investor with a rate of return smaller than the rate that is appropriate for the security's risk level (morganstanleycontent).
· In the case of overpriced securities, investors will sell the security until the price drops and the security is forced back up onto the security market line (SML) because the expected returns are less than that predicted by the CAPM equation (weallsomwhere, 2010).
8. Success of CAPM:
The strength of CAPM have examined by a number of studies over the past two decades. The result reported in these studies that CAPM is the one that most often use for evaluating the risk of the cash flow from a project by financial managers and appearing at the suitable discount rate to use in assessing the plan. Maybe, the CAPM still alive because of the economic importance of the empirical evidence adjacent to the CAPM stated in empirical studies in vague and the theory behind the CAPM has an innate appeal that is hard to thrash using the other models.
8.1. Shortcomings of CAPM:
The some limitations of CAPM to acquire the cost of capital to evaluate an investment project are following:
· Only systematic risk needs to be confined as unsystematic risk has been diversified away. This is not the case in entities managed by families or individuals where the shareholders are not likely to be entirely diversified.
· Risk can be summarized in a single figure (beta) in CAPM.
· The calculation of discount rate may not be suitable for the whole life of the project because CAPM is a single period model, so it is important that beta stays quite stable over time if it is to be used in approximating a discount rate.
· Close association with a surrogate body is tricky as it thinks close comparison of activities and business risk (Ogilvie, 2008).
9. What is Arbitrage Pricing Theory (NYSEMKT:APT):
The APT theory was proposed by Stephen Ross in 1976. APT theory speculates that investors can forecast the return on asset through its performance in connection with autonomous macroeconomic variables and common risk factors. APT theory are commonly used by stock investors to classify stocks that are mispriced, then sell stocks that are too high and buy stocks that are too low (InvestorGlossary).
9.1. CAPM v/s APT:
· CAPM formula is additional in terms of what you could earn elsewhere while APT formula is more precise to that stock because; APT does not apply the whole market's return whereas, CAPM concern the rate of return of the entire market.
· The data which APT uses is specific to that stock. Whereas, a lot of objective data which commonly accessible are used by CAPM (ehow).
· In practice, CAPM works better than APT. Because APT has some estimation error. In CAPM the required return is more reasonably accurate as compared with APT, which does not provide the actual reason that how many factors should we use and what they are. In theoretically APT may be advanced, but in practical this is cancelled out because the inaccurate required return (Michailidis, 2007).
10. Conclusion:
According to the previous study it explains that CAPM was quite unbeaten in forecasting the cost of assets. Even though the CAPM model was not absolutely perfect but the strength of CAPM is correct and it still gives a valid explanation about the prices of asset that the return which is required, is comparative to the estimated surplus and organized hazards of marketplace. Errors of CAPM model can be recovered through improved surrogates for risk free rate and the market with enhanced econometric methods.
11. Bibliography:
Bogleheads, 2012. CAPM  Capital Asset Pricing Model. [online] Available at: http://www.bogleheads.org/wiki/CAPM__Capital_Asset_Pricing_Model [Accessed 22 April 2013]
Bryant, B.J., 2013. Practical use of a CAPM. [online] Available at: http://www.ehow.com/way_5818803_practicalusecapm.html [Accessed 22 April 2013]
Farlex, 2012. Capital Asset Pricing Model. [online] Available at: http://financialdictionary.thefreedictionary.com/CAPM [Accessed 24 April 2013]
Gilani, M., n.d. Uses of CAPM. [online] Available at: http://www.ehow.com/list_6526446_usescapm.html [Accessed 23 April 2013]
Grover, S., n.d. How to compare capm & apt. [online] Available at: http://www.ehow.co.uk/how_7508497_comparecapmapt.html [Accessed 24 April 2013]
Investor Glossary, 2013. Arbitrage Pricing Theory. [online] Available at: http://www.investorglossary.com/arbitragepricingtheory.htm [Accessed 28 April 2013]
McCracken, M., 2009. CAPM  The Capital Asset Pricing Model. [online] Available at: http://www.teachmefinance.com/capm.html [Accessed 23 April 2013]
Morgan Stanley, n.d. Overpriced Security. [online] Available at: http://morganstanleycontent.intuition.com/lms/glossary/a_to_z_definition.asp?188856 [Accessed 25 April 2013]
Ogilvie, J., 2008. Management Accounting. 2009 ed. USA: Elsevier.
Parikh, V., 2009. Capital Asset Pricing Model and Its Assumptions. [online] Available at: http://www.letslearnfinance.com/capitalassetpricingmodelanditsassumptions.html [Accessed 23 April 2013]
Quant, 2013. CAPM assumptions. [online] Available at: http://knowledgebase.abcquant.com/index.php?option=com_kb&task=article&article=58 [Accessed 23 April 2013]
Shapiro, A., n.d. Foundations of Finance: The Capital Asset Pricing Model (CAPM. [online] Available at: http://pages.stern.nyu.edu/~ashapiro/courses/B01.231103/FFL09.pdf [Accessed 26 April 2013]
SRK, 2010. Risk Analysis & Decision Making. [online] Available at: http://www.managementaccountancy.com/2010/10/riskanalysisdecisionmaking/ [Accessed 24 April 2013]
Taylor, B., 2005. An Empirical Evaluation of the Capital Asset Pricing Model. [online] Available at: http://economics.fundamentalfinance.com/capm.php [Accessed 29 April 2013]
Wall Street Oasis, n.d. Security Market Line (SML) Definition. [online] Available at: http://www.wallstreetoasis.com/financedictionary/whatisthesecuritymarketlinesml [Accessed 26 April 2013]
Wall Street Oasis, 2010. Portfolio Theory Capital Asset Pricing Model. [online] Available at: http://www.weallstartsomewhere.com/finance/capm.pdf [Accessed 24 April 2013]
Young Investor Program, n.d. Risk and Return. [online] Available at: http://fycs.ifas.ufl.edu/younginvestor/module3/mod3sec12.shtml [Accessed 23 April 2013]