财务管理第十三章课件.pptx

Chapter 13Return, Risk, and the Security Market LineMcGraw-Hill/IrwinCopyright 2013 by The McGraw-Hill Companies, Inc. All rights reserved.Key Concepts and Skills Know how to calculate expected returns Understand the impact of diversification Understand the systematic risk principle Understand the security market line Understand the risk-return trade-off Be able to use the Capital Asset Pricing Model13-2Chapter Outline Expected Returns and Variances Portfolios Announcements, Surprises, and Expected Returns Risk: Systematic and Unsystematic Diversification and Portfolio Risk Systematic Risk and Beta The Security Market Line The SML and the Cost of Capital: A Preview13-3Expected Returns Expected returns are based on the probabilities of possible outcomes In this context, “expected” means average if the process is repeated many times The “expected” return does not even have to be a possible returnniiiRpRE1)(13-4Example: Expected ReturnsStateProbabilityCTBoom0.31525Normal0.51020Recession ? 2 1 RC = .3(15) + .5(10) + .2(2) = 9.9% RT = .3(25) + .5(20) + .2(1) = 17.7%13-5 Suppose you have predicted the following returns for stocks C and T in three possible states of the economy. What are the expected returns?Variance and Standard Deviation Variance and standard deviation measure the volatility of returns Using unequal probabilities for the entire range of possibilities Weighted average of squared deviationsniiiRERp122)(13-6Example: Variance and Standard Deviation Consider the previous example. What are the variance and standard deviation for each stock? Stock C2 = .3(15-9.9)2 + .5(10-9.9)2 + .2(2-9.9)2 = 20.29 = 4.50% Stock T2 = .3(25-17.7)2 + .5(20-17.7)2 + .2(1-17.7)2 = 74.41 = 8.63%13-7Another Example Consider the following information:StateProbabilityABC, Inc. (%)Boom.2515Normal.508Slowdown.154Recession.10-3 What is the expected return? What is the variance? What is the standard deviation?13-8Portfolios A portfolio is a collection of assets An assets risk and return are important in how they affect the risk and return of the portfolio The risk-return trade-off for a portfolio is measured by the portfolio expected return and standard deviation, just as with individual assets13-9Example: Portfolio Weights Suppose you have $15,000 to invest and you have purchased securities in the following amounts. What are your portfolio weights in each security? $2000 of C $3000 of KO $4000 of INTC $6000 of BPC: 2/15 = .133KO: 3/15 = .2INTC: 4/15 = .267BP: 6/15 = .413-10Portfolio Expected Returns The expected return of a portfolio is the weighted average of the expected returns of the respective assets in the portfolio You can also find the expected return by finding the portfolio return in each possible state and computing the expected value as we did with individual securitiesmjjjPREwRE1)()(13-11Example: Expected Portfolio Returns Consider the portfolio weights computed previously. If the individual stocks have the following expected returns, what is the expected return for the portfolio?C: 19.69%KO: 5.25%INTC: 16.65%BP: 18.24% E(RP) = .133(19.69) + .2(5.25) + .267(16.65) + .4(18.24) = 15.41%13-12Portfolio Variance Compute the portfolio return for each state:RP = w1R1 + w2R2 + + wmRm Compute the expected portfolio return using the same formula as for an individual asset Compute the portfolio variance and standard deviation using the same formulas as for an individual asset13-13Example: Portfolio Variance Consider the following information Invest 50% of your money in Asset AStateProbabilityABBoom.430%-5%Bust.6-10%25% What are the expected return and standard deviation for each asset? What are the expected return and standard deviation for the portfolio?Portfolio12.5%7.5%13-14Another Example Consider the following informationStateProbabilityXZBoom.2515%10%Normal.6010%9%Recession.155%10% What are the expected return and standard deviation for a portfolio with an investment of $6,000 in asset X and $4,000 in asset Z?13-15Expected vs. Unexpected Returns Realized returns are generally not equal to expected returns There is the expected component and the unexpected component At any point in time, the unexpected return can be either positive or negative Over time, the average of the unexpected component is zero13-16Announcements and News Announcements and news contain both an expected component and a surprise component It is the surprise component that affects a stocks price and therefore its return This is very obvious when we watch how stock prices move when an unexpected announcement is made or earnings are different than anticipated13-17Efficient Markets Efficient markets are a result of investors trading on the unexpected portion of announcements The easier it is to trade on surprises, the more efficient markets should be Efficient markets involve random price changes because we cannot predict surprises13-18Systematic Risk Risk factors that affect a large number of assets Also known as non-diversifiable risk or market risk Includes such things as changes in GDP, inflation, interest rates, etc.13-19Unsystematic Risk Risk factors that affect a limited number of assets Also known as unique risk and asset-specific risk Includes such things as labor strikes, part shortages, etc.13-20Returns Total Return = expected return + unexpected return Unexpected return = systematic portion + unsystematic portion Therefore, total return can be expressed as follows: Total Return = expected return + systematic portion + unsystematic portion13-21Diversification Portfolio diversification is the investment in several different asset classes or sectors Diversification is not just holding a lot of assets For example, if you own 50 Internet stocks, you are not diversified However, if you own 50 stocks that span 20 different industries, then you are diversified13-22Table 13.713-23The Principle of Diversification Diversification can substantially reduce the variability of returns without an equivalent reduction in expected returns This reduction in risk arises because worse than expected returns from one asset are offset by better than expected returns from another However, there is a minimum level of risk that cannot be diversified away and that is the systematic portion13-24Figure 13.113-25Diversifiable Risk The risk that can be eliminated by combining assets into a portfolio Often considered the same as unsystematic, unique or asset-specific risk If we hold only one asset, or assets in the same industry, then we are exposing ourselves to risk that we could diversify away13-26Total Risk Total risk = systematic risk + unsystematic risk The standard deviation of returns is a measure of total risk For well-diversified portfolios, unsystematic risk is very small Consequently, the total risk for a diversified portfolio is essentially equivalent to the systematic risk13-27Systematic Risk Principle There is a reward for bearing risk There is not a reward for bearing risk unnecessarily The expected return on a risky asset depends only on that assets systematic risk since unsystematic risk can be diversified away13-28Measuring Systematic Risk How do we measure systematic risk?We use the beta coefficient What does beta tell us? A beta of 1 implies the asset has the same systematic risk as the overall market A beta 1 implies the asset has more systematic risk than the overall market13-29Table 13.8 Selected BetasInsert Table 13.8 here13-30Total vs. Systematic Risk Consider the following information: Standard DeviationBetaSecurity C20%1.25Security K30%0.95 Which security has more total risk? Which security has more systematic risk? Which security should have the higher expected return?13-31Work the Web Example Many sites provide betas for companies Yahoo Finance provides beta, plus a lot of other information under its Key Statistics link Click on the web surfer to go to Yahoo Finance Enter a ticker symbol and get a basic quote Click on Key Statistics13-32Example: Portfolio Betas Consider the previous example with the following four securitiesSecurityWeightBetaC.1332.685KO.20.195INTC.2672.161BP.42.434 What is the portfolio beta? .133(2.685) + .2(.195) + .267(2.161) + .4(2.434) = 1.94713-33Beta and the Risk Premium Remember that the risk premium = expected return risk-free rate The higher the beta, the greater the risk premium should be Can we define the relationship between the risk premium and beta so that we can estimate the expected return? YES!13-34Example: Portfolio Expected Returns and BetasRfE(RA)A13-35Reward-to-Risk Ratio: Definition and Example The reward-to-risk ratio is the slope of the line illustrated in the previous example Slope = (E(RA) Rf) / (A 0) Reward-to-risk ratio for previous example = (20 8) / (1.6 0) = 7.5 What if an asset has a reward-to-risk ratio of 8 (implying that the asset plots above the line)? What if an asset has a reward-to-risk ratio of 7 (implying that the asset plots below the line)?13-36Market Equilibrium In equilibrium, all assets and portfolios must have the same reward-to-risk ratio, and they all must equal the reward-to-risk ratio for the marketMfMAfARRERRE)()(13-37Security Market Line The security market line (SML) is the representation of market equilibrium The slope of the SML is the reward-to-risk ratio: (E(RM) Rf) / M But since the beta for the market is always equal to one, the slope can be rewritten Slope = E(RM) Rf = market risk premium13-38The Capital Asset Pricing Model (CAPM) The capital asset pricing model defines the relationship between risk and return E(RA) = Rf + A(E(RM) Rf) If we know an assets systematic risk, we can use the CAPM to determine its expected return This is true whether we are talking about financial assets or physical assets13-39Factors Affecting Expected Return Pure time value of money: measured by the risk-free rate Reward for bearing systematic risk: measured by the market risk premium Amount of systematic risk: measured by beta13-40Example - CAPM Consider the betas for each of the assets given earlier. If the risk-free rate is 4.15% and the market risk premium is 8.5%, what is the expected return for each?Security BetaExpected Return C2.6854.15 + 2.685(8.5) = 26.97% KO0.1954.15 + 0.195(8.5) = 5.81% INTC2.1614.15 + 2.161(8.5) = 22.52% BP2.4344.15 + 2.434(8.5) = 24.84%13-41Figure 13.413-42Quick Quiz How do you compute the expected return and standard deviation for an individual asset? For a portfolio? What is the difference between systematic and unsystematic risk? What type of risk is relevant for determining the expected return? Consider an asset with a beta of 1.2, a risk-free rate of 5%, and a market return of 13%. What is the reward-to-risk ratio in equilibrium? What is the expected return on the asset?13-43Comprehensive Problem The risk free rate is 4%, and the required return on the market is 12%. What is the required return on an asset with a beta of 1.5? What is the reward/risk ratio? What is the required return on a portfolio consisting of 40% of the asset above and the rest in an asset with an average amount of systematic risk?13-44End of Chapter13-45