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Risk, Returns, CAPM and the Cost of Capital. Where does the discount rate come from?. Today’s plan. Review some concepts in bond valuation Risk and returns 75 years of capital market history How to measure risk Individual security risk Portfolio risk Diversification Unique risk
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Risk, Returns, CAPM and the Cost of Capital Where does the discount rate come from? FIN 819: lecture 4
Today’s plan • Review some concepts in bond valuation • Risk and returns • 75 years of capital market history • How to measure risk • Individual security risk • Portfolio risk • Diversification • Unique risk • Systematic risk or market risk • Measure market risk: beta
Today’s plan (continue) • Portfolio rules and diversification • Measure market risk: beta • CAPM • WACC
The Value of an Investment of $1 in 1926 6402 2587 64.1 48.9 16.6 Index 1 Year End Source: Ibbotson Associates
The Value of an Investment of $1 in 1926 Real returns 660 267 6.6 5.0 1.7 Index 1 Year End Source: Ibbotson Associates
Rates of Return 1926-2000 Percentage Return Year • Source: Ibbotson Associates
Risk premium • The risk premium is the difference between the expected rate of return on a risky security and the expected rate of return on risk-free government bonds or T-bills. • Over the last century, the average risk premium is about 7% for stocks.
Why do investors command a risk premium for stocks? • When investors invest in a risky security, they require a risk premium, or they require a higher expected rate of return than investment in a risk-free security. • How to measure the risk of a security?
Measuring Risk In financial markets, we use the variance or volatility of a security return to measure its risk. Variance – Weighted average value of squared deviations from mean. Standard Deviation – Weighted average value of absolute deviations from mean and is also the square root of the variance
Calculating the risk of a security • We can use two approaches to calculate the risk of a security, depending on what kind of information you are given. • Using the basic definition of expectation and variance to calculate • Using the portfolio rule to calculate • In fact, these two approaches are exactly the same, but the second one can omit some detail calculation.
Some basic concepts • Before we go on to show how to use two approaches to calculate risk, let’s first review some basic formula for Expectation and Variance • Let X be a return of a security in the next period. Then we have
Portfolio • A portfolio is a set of securities and can be regarded as a security. • If you invest W US dollars in a portfolio of n securities, let Wi be the money invested in security i, then the portfolio weight on stock i is , with property
Example 1 • Suppose that you want to invest $1,000 in a portfolio of IBM and GE. You spend $200 on IBM and the other on GE. What is the portfolio weight on each stock?
Example 2 • Suppose that you have $1,000 and borrow another $1,000 from the bank to invest in IBM and GE. You spend $500 on IBM and the other on GE. What is the portfolio weight on each stock?
Three portfolio rules A: The return of a portfolio is the weighted average of the returns of the securities in the portfolio. B: The expected return of a portfolio is the weighted average of the expected returns of the securities in the portfolio. C: The Beta of a portfolio is the weighted average of the Betas of the securities in the portfolio.
Portfolio risk with two stocks The variance of a two stock portfolio is the sum of these four boxes
1 2 3 4 5 6 N 1 2 3 4 5 6 N Portfolio risk for N securities
Example • Consider a portfolio of two stocks: IBM and GL. • What is the expected return and standard deviation of the portfolio?
Two types of risks Unique Risk - Risk factors affecting only that firm. Also called “firm-level risk.” Market Risk - Economy-wide sources of risk that affect the overall stock market. Also called “systematic risk.”
Diversification • What have your observed from the above example • Risk for each individual stock • Risk for your portfolio • Diversification: put a lot of different assets in a portfolio to reduce risk • Why can diversification be used to reduce risk?
Market risk and Beta Market Portfolio - Portfolio of all assets in the economy. In practice a broad stock market index, such as the S&P 500, is used to represent the market portfolio. Beta - Sensitivity of a stock’s return to the return on the market portfolio. Beta- measures systematic risk
Beta and market risk Covariance with the market Variance of the market
Some true or false questions 1. A market index is used to measure performance of a broad-based portfolio of stocks. 2. Long-term corporate bonds are riskier than common stocks. 3.If one portfolio's variance exceeds that of another portfolio, its standard deviation will also be greater than that of the other portfolio. 4. Portfolio weights are always positive.
Some true or false questions 5. Standard deviation can be calculated as the square of the variance. 6. Market risk can be eliminated in a stock portfolio through diversification. 7. Macro risks are faced by all common stock investors. 8. The risk that remains in a stock portfolio after efforts to diversify is known as unique risk. 9. We use the standard deviation of future stock prices to measure the risk of a stock.
Measuring Market Risk • Market Portfolio • It is a portfolio of all assets in the economy. In practice a broad stock market index, such as the S&P 500 is used to represent the market portfolio. The market return is denoted by Rm • Beta (β) • Sensitivity of a stock’s return to the return on the market portfolio, • Mathematically,
An intuitive example for Beta Turbo Charged Seafood has the following % returns on its stock, relative to the listed changes in the % return on the market portfolio. The beta of Turbo Charged Seafood can be derived from this information.
Measuring Market Risk (continue) • When the market was up 1%, Turbo average % change was +0.8% • When the market was down 1%, Turbo average % change was -0.8% • The average change of 1.6 % (-0.8 to 0.8) divided by the 2% (-1.0 to 1.0) change in the market produces a beta of 0.8. β=1.6/2=0.8
Another example • Suppose we have following information: Market Stock A Stock B State -6% -8% -10% bad 24% 32% good 38% a. What is the beta for each stock? b. What is the expected return for each stock if each scenario is equally likely? c. What is the expected return for each stock if the probability for good economy is 20%?
Solution a. b. c.
Portfolio Betas • Diversification reduces unique risk, but not market risk. • The beta of a portfolio will be an weighted average of the betas of the securities in the portfolio. • What is the beta of the market portfolio? • What is the beta of the risk-free security?
Example • Suppose you have a portfolio of IBM and Dell with a beta of 1.2 and 2.2, respectively. If you put 50% of your money in IBM, and the other in Dell, what is the beta of your portfolio Beta of your portfolio =0.5*1.2 +0.5*2.2=1.7
Market risk and risk premium • Risk premium for bearing market risk • The difference between the expected return required by investors and the risk-free asset. • Example, the expected return on IBM is 10%, the risk-free rate is 5%, and the risk premium is 10% -5%=5% • If a security ( an individual security or a portfolio) has market or systematic risk, risk-averse investors will require a risk premium.
CAPM (Capital Asset Pricing Model) • The risk premium on each security is proportional to the market risk premium and the beta of the security. • That is,
Security market line • The graphic representation of CAPM in the expected return and Beta plane Security Market Line rf
Project Risk and cost of the capital • In capital budgeting, in order to calculate the NPV of the project, we need to measure the risk of the project and thus find out the discount rate (the cost of capital) • We can use Beta of the project cash flows to measure the risk of the project and use CAPM to get the expected return required by investors
Example 1 • Based on the CAPM, ABC Company has a cost of capital of 17%. (4 + 1.3(10)). A breakdown of the company’s investment projects is listed below. • 1/3 Nuclear Parts: β=2.0 • 1/3 Computer Hard Drive: β =1.3 • 1/3 Dog Food Production: β =0.6 • When evaluating a new dog food production investment, which cost of capital should be used and how much?
Solution • Since dog food projects may have similar systematic risk to the dog food division, we use a beta of 0.6 to measure the risk of the projects to be taken. • Thus the expected return on the project or the cost of capital is 0.04+0.6*(0.1)=0.l or 10%
Example 2 • Stock A has a beta of .5 and investors expect it to return 5%. Stock B has a beta of 1.5 and investors expect it to return 13%. What is the market risk premium and the expected rate of return on the market portfolio?
Solution • According to the CAPM
Example 3 • You have $1 million of your own money and borrow another $1 million at a risk-free rate of 4% to invest in the market portfolio. The expected return for the market portfolio is 12%, what is the expected return on your portfolio?
Solution • We can use two approaches to solve it: • First, the expected rate of return of a portfolio is the weighed average of the expected rates of return of the securities in the portfolio. • Second , the beta of a portfolio is the weighed average of the betas of the securities in the portfolio. Then use the CAPM to get the expected rate of return.
Solution (continue) • First approach • Second approach
The cost of capital Cost of Capital • The expected return the firm’s investors require if they invest in securities or projects with comparable degrees of risk.
Cost of capital with tax benefit • When tax benefit of debt financing is considered, the company cost of capital is as
The cost of capital for the bond • The cost of capital for the bond • It is the YTM, the expected return required by the investors. • That is • The expected return on a bond can also be calculated by using CAPM