Lecture 7 Introduction to Risk, Return, and the Opportunity Cost of Capital Managerial Finance FINA 6335 Ronald F. Singer
7-2 Topics Covered 72 Years of Capital Market History Measuring Risk Portfolio Risk Beta and Unique Risk Diversification
7-3 The Value of an Investment of $1 in Index Year End
7-4 The Value of an Investment of $1 in 1926 Index Year End Real returns
7-5 Rates of Return Year Percentage Return
7-6 Measuring Risk Variance - Average value of squared deviations from mean. A measure of volatility. Standard Deviation - Average value of squared deviations from mean. A measure of volatility
7-7 Measuring Risk Coin Toss Game-calculating variance and standard deviation
7-8 Measuring Risk Return % # of Years
7-9 Measuring Risk Diversification: Strategy designed to reduce risk by spreading the portfolio across many investments. Unique Risk: Risk factors affecting only that firm. Also called “diversifiable risk.” Market Risk: Economy-wide sources of risk that affect the overall stock market. Also called “systematic risk.”
7-10 Measuring Portfolio Return
7-11 Measuring Risk
7-12 Measuring Risk
7-13 Portfolio Risk The variance of a two stock portfolio is the sum of these four boxes:
7-14 Suppose you invest $55 in Bristol-Myers and $45 in McDonald’s. The expected dollar return on your BM is.10 x 55 = 5.50 and on McDonald’s it is.20 x 45 = The expected dollar return on your portfolio is = The portfolio rate of return is 14.50/100 =.145 or 14.5%. Assume a correlation coefficient of Assume the Standard Deviation of BM is 17.1%, and of McD is 20.8% Example
7-15 Example
7-16 Portfolio Risk The shaded boxes contain variance terms; the remainder contain covariance terms N N STOCK To calculate portfolio variance add up the boxes
7-17 Beta and Unique Risk beta Expected return Expected market return 10% %+10% stock -10% 1. Total risk = diversifiable risk + market risk 2. Market risk is measured by beta, the sensitivity to market changes.
7-18 Beta and Unique Risk Market Portfolio - Portfolio of all assets in the economy. In practice a broad stock market index, such as the S&P Composite, is used to represent the market. Beta - Sensitivity of a stock’s return to the return on the market portfolio.
7-19 Beta and Unique Risk Covariance with the market Variance of the market