Text of 1 CHAPTER 9 Risk and Rates of Return Stand-alone risk (statistics review) Portfolio risk...
1 CHAPTER 9 Risk and Rates of Return Stand-alone risk (statistics review) Portfolio risk (investor view) -- diversification important Risk & return: CAPM/SML (market equilibrium)
2 Risk is viewed primarily from the stockholder perspective Management cares about risk because stockholders care about risk. If stockholders like or dislike something about a company (like risk) it affects the stock price. Risk affects the discount rate for future returns -- directly affecting the multiple (P/E ratio) Thus, the concern is still about the stock price. Stockholders have portfolios of investments they have stock in more than just one company and a great deal of flexibility in which stocks they buy.
3 What is investment risk? Investment risk pertains to the uncertainty regarding the rate of return. Especially when it is less than the expected (mean) return. The greater the chance of low or negative returns, the riskier the investment.
4 Return = dividend + capital gain or loss Dividends are relatively stable Stock price changes (capital gains/losses) are the major uncertain component There is a range of possible outcomes and a likelihood of each -- a probability distribution.
5 Expected Rate of Return The mean value of the probability distribution of possible returns It is a weighted average of the outcomes, where the weights are the probabilities
6 Expected Rate of Return (k hat)
7 Investment Alternatives
8 Why is the T-bill return independent of the economy? Will return be 8% regardless of the economy?
9 Do T-bills really promise a completely risk-free return? No, T-bills are still exposed to the risk of inflation. However, not much unexpected inflation is likely to occur over a relatively short period.
10 Do the returns of HT and Coll. move with or counter to the economy? High Tech: With. Positive correlation. Typical. Collections: Countercyclical. Negative correlation. Unusual.
11 Calculate the expected rate of return for each alternative: k = expected rate of return k HT = (-22%)0.1 + (-2%)0.20 + (20%)0.40 + (35%)0.20 + (50%)0.1 = 17.4% ^ ^ ^
12 HT appears to be the best, but is it really? ^ Calculate others on your own
13 Whats the standard deviation of returns for each alternative? = standard deviation
14 Normal Distribution
15 One often assumes that data are from an approximately normally distributed population. thennormally distributed about 68.26% of the values are at within 1 standard deviation away from the mean, 95.46% of the values are within two standard deviations and 99.73% lie within 3 standard deviations. In a sample of observations
17 Standard deviation ( i ) measures total, or stand- alone, risk. The larger the i, the lower the probability that actual returns will be close to the expected return.
18 Expected Returns vs. Risk: *Return looks low relative to
19 Coefficient of variation (CV): Standardized measure of dispersion about the expected value: Shows risk per unit of return.
20 Portfolio Risk & Return Assume a two-stock portfolio with $50,000 in HighTech and $50,000 in Collections. Calculate k p and p.
21 Portfolio Expected Return, k p k p is a weighted average: k p = 0.5(17.4%) + 0.5(1.7%) = 9.6% k p is between k HT and k COLL. ^ ^ ^ ^ ^^
22 Alternative Method: k p = (3.0%)0.1 + (6.4%)0.20 + (10.0%)0.4 + (12.5%)0.20 + (15.0%)0.1 = 9.6% ^
23 = 3.3% Note: you can work the variance calculation in either decimal or percentage
24 p = 3.3% is much lower than that of either stock (20% and 13.4%). p = 3.3% is also lower than avg. of HT and Coll, which is 16.7%. Portfolio provides avg. return but lower risk. Reason: diversification. Negative correlation is present between HT and Coll but is not required to have a diversification effect
25 General Statements about risk: Most stocks are positively correlated. r k,m 0.65. You still get a lot of diversification effect at.65 correlation 35% for an average stock. Combining stocks generally lowers risk.
26 What would happen to the riskiness of a 1-stock portfolio as more randomly selected stocks were added? p would decrease because the added stocks would not be perfectly correlated
27 # stocks in portfolio 10203040......1500+ Company Specific risk Market Risk p % 35 20 0 Total Risk, P
28 As more stocks are added, each new stock has a smaller risk- reducing impact. p falls very slowly after about 40 stocks are included. The lower limit for p is about 20% = M.
29 Decomposing RiskSystematic (Market) and Unsystematic (Business-Specific) Risk Fundamental truth of the investment world The returns on securities tend to move up and down together Not exactly together or proportionately Events and Conditions Causing Movement in Returns Some things influence all stocks (market risk) Political news, inflation, interest rates, war, etc. Some things influence only particular firms (business-specific risk) Earnings reports, unexpected death of key executive, etc. Some things affect all companies within an industry A labor dispute, shortage of a raw material
30 Total = Market + Firm specific risk risk risk Market risk is that part of a securitys risk that cannot be eliminated by diversification. Firm-specific risk is that part of a securitys risk which can be eliminated with diversification.
31 By forming portfolios, we can eliminate nearly half the riskiness of individual stocks (35% vs. 20%). (actually35% vs. 20% is a 43%reduction)
32 If you chose to hold a one- stock portfolio and thus are exposed to more risk than diversified investors, would you be compensated for all the risk you bear? CAPM -- Capital Asset Pricing Model
33 NO! Stand-alone risk as measured by a stocks or CV is not important to well-diversified investors. Rational, risk averse investors are concerned with p, which is based on market risk.
34 Beta measures a stocks market risk. It shows a stocks volatility relative to the market. Beta shows how risky a stock is when the stock is held in a well-diversified portfolio. The higher beta, the higher the expected rate of return.
35 How are betas calculated? Run a regression of past returns on Stock i versus returns on the market. The slope coefficient is the beta coefficient.
36 - 505101520 20 15 10 5 -5 -10 Yeark M k i 115%18% 2-5-10 31216... k i = -2.59 + 1.44 k M Illustration of beta = slope: Regression line
37 Find beta: Statistics program or spreadsheet regression Find someones estimate of beta for a given stock on the web Generally use weekly or monthly returns, with at least a year of data
38 If beta = 1.0, average risk stock. (The market portfolio has a beta of 1.0.) If beta > 1.0, stock riskier than average. If beta < 1.0, stock less risky than average. Most stocks have betas in the range of 0.5 to 1.5. Some ag. related companies have betas less than 0.5
39 =1, get the market expected return 1, get an expected return greater than the market
40 Answer: Yes, if the correlation between k i and k M is negative. Then in a beta graph the regression line will slope downward. Negative beta -- rare Can a beta be negative?
41 HT T-bills b=0 kiki kMkM - 2002040 40 20 -20 b = 1.29 Coll b = -0.86
42 Riskier securities have higher returns, so the rank order is O.K.
43 Given the beta of a stock, a theoretical required rate of return can be calculated. The Security Market Line (SML) is used. SML: k i = k RF + (k M - k RF )b i MRP MRP= market risk premium
44 k i = k RF + (k M - k RF )b i
45 For Term Projects (2013) Use K RF = 3.0%; this is a bit more than the current 10 year treasury rate of 2.75%. Sometimes analysts use a shorter term rate and short term treasuries are still extremely low, but we are going to use 3.0%. Use MRP = 5%. This is MRP, not K M. The historical average MRP is about 5%. Find your own beta from the web On Yahoo Finance look up your company and then the key statistics tab on the left will give you their beta