MANAGERIAL FINANCE 410 (Rev Sp’15) STUDENT LECTURE NOTE 4 I. Fundamentals of Risk and Return A. Risk and Risk-Types 1. _____ is THE four-letter word in Finance. Everything has something to do with risk. 2. Investment risk: the possibility that the return on your investment does not match your expectations. You should understand the difference between exante (expected) risk versus ex-post (realized/ historical) risk. 3. Interest-rate risk: Rising or falling interest rates due to market conditions impact the rates you pay or earn when you borrow or invest, as well as the value of the investments in your portfolio. 4. Inflation risk: Changes in the general price level mean that the purchasing power of your money may _______ (rising prices) or _______ (falling prices). 5. Liquidity risk: describes how easily (or inexpensive) it is to convert a given asset (something you own) into cash. Different types of assets have varying degrees of liquidity. Cash (or savings/checking accounts) by definition is the most liquid asset. Figure 4.1 below provides a general idea of potential investments and their relative liquidity. Finance Elective: MV Analysis 1 Assets FIGURE 4.1 Liquidity Comment Publicly-traded Stocks, High through Stock and Bond Mutual secondary markets. Funds and REITs Bank CDs and T-Bills Medium High Corporate, Treasury and Municipal Bonds Real Estate and Used Vehicles (not including classic cars) Collectibles like Antiques, Art, Classic Cars, Comic Books, Firearms, Jewelry, etc. the Easy to sell through broker or account manager at market price. CDs are easy to cash out prior to maturity however interest penalty may be substantial. Medium High as the Bonds trading at a discount secondary market is not mean that you will not nearly as active as for receive face value if sold stocks. before maturity. Medium to Low as market The price concession to conditions are very liquidate quickly may be important. substantial. The keys are demand and desirability. Generally Low To sell these items without a large price concession it is critical to find the right buyer. 6. Income risk: Losing one’s job is never a good thing whether due to the economic situation, company factors or for personal reasons. Ideally, experts recommend you have savings equal to ___ months of income for such a job-loss (or medical) emergency. 7. Personal risk: describes risks that are basically due to the decisions you make in life, albeit some may be less in your control than others. These may include purchase, career, health and safety decisions. B. Return Types and Calculating the Rate of Return 1. Return: An economist would say the return gained through an investment is a reward earned for Finance Elective: MV Analysis 2 deferring consumption. A financial economist would say that return is the reward earned for bearing ____. 2. Again ex-ante (expected) return versus ex-post (realized/historical) return. There is no risk in realized returns. 3. Rate of return is typically measured in relation to the initial investment and is stated on an annual percentage basis. In its simplest form, the ________ (annual) percentage return (PR1) is calculated as in (4.1) below. This is also the most basic formula to calculate percentage change in general. P P P PR1 = 1 0 = 1 1, P0 P0 (4.1) Where: P0 is the price at time zero, and P1 is the price one year later. Ex. 4.1 Assume today is April 12th, 2004 and the price of a gallon of regular, unleaded gasoline at the Hammond Racetrac station is $1.769. If the gas price at this same time last year (April 2003) was $1.479, by what percentage have gas prices changed over the past year? $1.769 $1.479 $1.769 A4.1. PR1(%) = = $1.479 1 $1.479 = _______ = _______. Finance Elective: MV Analysis 3 4. Return on investment usually is going to be measured over multi-year investment periods. However, what investors should be interested in for comparative purposes will be __________ rates of return. When an asset’s beginning (present) value (PV0), ending (future) value (FVt) and the term of investment (t) are known (and there are no interim cash flows) then the following equation can be used to calculate the (implicit) percentage rate of return earned on the investment (r%). 1/t FV r(%) = t 1, PV0 (4.2) Ex. 4.2 Assume again that today is April 12th, 2004 and the unleaded gas price (per gallon) at the Hammond Racetrac station is $1.769. a) If the gas price on this same date in 2009 (five years later) was $1.899, what is the annualized percentage price change over this period? b) Does this small average price increase surprise you? Given what you know about gas prices over this period, especially Summer and Fall of 2008, what does this knowledge make you realize about risk (compared to the average annualized return)? Finance Elective: MV Analysis 4 1 A4.2a) r(%) $1.899 5 = 1 = _______ = _______. $1.769 A4.2b) Clearly average price changes do not tell the whole story. From $1.769 (mid-2004) to over $4.00 (in early July 2008) petrol prices have been very volatile. See graph below. Thus, one must also specifically assess risk when considering potential investments. Ave rage U.S. Gas oline Price s Cents per gallon 450 400 350 300 250 200 150 Jan-04 May-05 Oct-06 Feb-08 Jul-09 C. A Look at Historical Risk and Return for the Major Asset Classes 1. Cash: Does not literally mean just the (paper) money stuffed under your mattress, in your purse or wallet. It means very liquid, very ___ risk and very short-term debt securities. Also termed money market instruments these also include other investments like Treasury-Bills, savings deposits, CDs and commercial paper. 2. Bonds: Debt instruments that have a _____ maturity Finance Elective: MV Analysis 5 than cash. These assets are represented by long-term Treasury Notes and Bonds, Municipal, Corporate and Foreign bonds. 3. Stocks: There a few hundred stocks issued by the largest corporations in America that are quite visible and trade very frequently. Although this is not quite exact, the stocks in the S&P 500 Index may be thought of as comprising the _________ stock class. There are a few thousand other publicly-traded midcap and small-cap stocks. Stocks are also sometimes categorized as “value stocks” or “growth stocks”. 4. Other Assets: There are other asset classes like mutual funds, ETFs, hedge funds, derivatives, foreign investments, real estate (also REITs), art, collectibles, etc. 5. Figure 4.2 below depicts the historical risk-return relationship for the periods of 1926-2007 and the more recent period of 1970-2007. Figure 4.2 Asset Class U.S. Inflation 30-Day T-Bills Inter Gov’t Bonds L-T Gov’t Bonds L-T Corp Bonds S&P 500 Stocks Small-Cap Stocks 1926-2007 Return (%) Risk (%) Geom Arith St Devn 3.0 3.1 4.2 3.7 3.8 3.1 5.3 5.5 5.7 5.5 5.8 9.2 5.9 6.2 8.4 10.4 12.3 20.0 12.5 17.1 32.6 1970-2007 Return (%) Risk (%) Geom Arith St Devn 4.6 4.7 3.1 6.0 6.0 2.9 8.2 8.4 6.6 8.9 9.4 11.2 8.9 9.4 10.5 11.1 12.4 16.6 13.4 15.6 22.6 Source: Ibbotson Stocks, Bonds, Bills and Inflation®, SBBI® Valuation Yearbook, © Morningstar 2008. Finance Elective: MV Analysis 6 II. Measuring Return and Risk for Individual Securities A. Statistical Risk and Return Measures 1. Expected Return: E(R) is the probability-weighted, arithmetic average return. In other words, it is the ____-_____ return given the different possible states of nature, the associated returns and their respective probabilities of occurrence. 2. The Expected Return may be calculated as follows when the probabilities of the states of nature are different: n E(R) = (R) = [Ri * Probi] i 1 = (R1Prob1)+(R2Prob2)+…+(RnProbn). (4.3) 3. Formula (4.3) may be reformulated when the probability of each state of nature is ____-______ as is given below. This formula is usually applied to asset-return calculations that are based on annual, monthly, or daily data, etc. n Ri E(R’) = i 1 . n (4.3’) 4. The Excel Function used to calculate the mean return (assuming equi-likely probabilities as in Finance Elective: MV Analysis 7 (4.3’)) is AVERAGE. Its form is given below. In this Excel equation (and also the next two) the values used in the calculation will typically be in the form of an ARRAY, i.e., (aa:zz) which refers to the range of values from cell aa to cell zz. =AVERAGE(number1,[number2],… ) (E4.1) 5. When monthly prices are used to calculate (monthly) returns, the average needs to be multiplied by 12 to annualise it as in (E4.1A). =AVERAGE(number1,[number2],… ) * 12 (E4.1A) B. Standard Deviation: A way to measure the dispersion of possible outcomes. It is found as the square root of the probability-weighted, summed, squared deviation of each return from the mean. Thus, the ____ concentrated the observations are around the mean, the lower the SD will be, and vice versa. 1. It is calculated on the basis of the Variance as follows: n Var(R) = 2(R) = ( Ri ) 2 * Probi . i 1 SD = (R) = Finance Elective: MV Analysis Var(R) . 8 (4.4) (4.5) 2. If the probabilities of each state of nature are __________ or, for example, returns are yearly, monthly, daily, etc., then the “population” variance and standard deviation formulas may be simplified as shown below.1 n 2 ( R i ) i 1 2 (R’) = . (4.4’) n (R’) = 2 ( R' ) . (4.5’) 3. The Excel functions to calculate the population variance and standard deviation (again, assuming equi-likely probabilities) are shown in (E4.2) and (E4.3), respectively. =VARP(number1,[number2],… ) (E4.2) =STDEVP(number1,[number2],… ) (E4.3) To annualise the variance it also needs to be multiplied by 12. So, that (E4.2) is annualised as in (E4.2A) as shown below. =VARP(number1,[number2],… ) * 12 (E4.2A) Because each deviation from the mean is squared to find the variance, and the square root is taken to calculate the standard deviation, the annualisation 1 Note: To find the “population” measures you need to use the VARP and STDEVP functions. The Excel VAR and STDEV functions calculate the “sample” measures. Finance Elective: MV Analysis 9 approach used for the standard deviation is to multiply the monthly STDEVP by the square root of 12 as in (E4.3A). =STDEVP(number1,[number2],… ) * 12 (E4.3A) Ex. 4.3 George Bekos (Fin 304-Fall’84, Fin 305-Win’85, Fin 348-Spr’85) is considering an investment in an 8% (RN) fixed-coupon bond. The real return he will earn on the bond will depend on the rate of inflation over the investment period. The inflation rates, real returns, the states of nature and the probability of that state occurring are given below. The Fisher Approximation (i.e., the equation shown below) is used to find the real interest rate. Based on this information determine the bond’s expected return and standard deviation. RR = RN – IE. Inflation Rate Very High = 9% High = 7% Moderate = 5% Low = 3% Probability 15% 25% 50% 10% Real Return - 1% +1% +3% +5% A4.3. (R) = (.15 -.01) + (.25 .01) + (.50 .03) + (.10 .05) = ____ = _____. 2(R) = [(-.01-.021)2 (.15) + (.01-.021)2 (.25) + (.03-.021)2 (.50) + (.05-.021)2 (.10)] Finance Elective: MV Analysis 10 = _________. (R) = .0002991 = _______ = ________. Ex. 4.3 extended Re-do Ex. 4.3 using formulas (4.3’), (4.4’) and (4.5’) under the assumption that the states of nature are equilikely. In general what should be expected to happen to these measures under this new assumption? A4.3. Ext. Expect mean return to go down as the lowest returns will get heavier weight and higher returns get less (or same) weight. Standard deviation goes up because returns which are farthest from mean get relatively greater weight. (R’) = [( -.01 + .01 + .03 + .05)/4] = ____ = _____. 2(R’) = (¼)[(-.01-.02)2 + (.01-.02)2 + (.03-.02)2 + (.05-.02)2] = _____. (R’) = .0005 = ________ = ______. C. Coefficient of Variation 1. The CV is a measure that may be used to quantify the Risk/Return Tradeoff. It measures the amount of risk borne per unit of expected return. Do simple example. Finance Elective: MV Analysis 11 2. It is calculated as follows: ( R) Coefficient of Variation (CV) = . ( R) (4.6) 3. Given the form of the measure in (4.6), it is useful to consider what makes for a superior investment: high expected project return; low standard deviation. Use ceteris paribus analysis. 4. Decision Criteria: Choose the project with the CV which has an [absolute] value closest to zero. Note: the technical aspect of this rule, i.e., an asset with a negative CV close to zero would technically be preferred to one with a high positive CV. Ex. 4.4 Kathleen Hendrix (F381 Su’08, F382 Fa’08) has collected monthly return data for the five-year period from 7/01/02 to 7/02/07 for the stock of Abbott Labs and seven Vanguard mutual funds. She has calculated the annualised average returns and standard deviations shown in the exhibit below. Your task is to calculate the coefficients of variation and to rank the risk-return tradeoffs for these eight assets, where rank=1, represents the best trade-off. Stock/Mutual Fund SYM Abbott Labs ABT GNMA Fund Inv Shares VFIIX Interm-Term Bond Index Inv VBIIX Shares Finance Elective: MV Analysis Retn(%) StDev(%) 12.346 17.851 3.691 2.839 5.110 5.438 12 CV 1.4459 0.7692 1.0642 Rank 8 1 6 Euro Stock Index Inv Shares Explorer Fund Inv Shares Mid-Cap Index Fund Inv Shares Tax-Managed Cap Appr Inv Shares Tax-Managed Cap Appr Adm Shares VEURX VEXPX VIMSX VMCAX 18.517 14.247 15.516 12.162 14.696 15.697 12.681 11.908 0.7936 1.1018 0.8173 0.9791 2 7 3 4 VTCLX 12.016 12.027 1.0009 5 A4.4. A sample calculation is shown for ABT below. St Dev 17.851% CVABT = = = ______. Retn 12.346% Figure 4.3: Annualization of Return & Risk Excel Functions Using Monthly Data Monthly Returns =AVERAGE * 12 =VARP * 12 =STDEVP * SQRT(12) =COVAR * 12 =CORREL Annualized Returns =AVERAGE =VARP/12 =STDEVP/SQRT(12) =COVAR/12 =CORREL Ex. 4.5 Jessica Poret (F382 Sp’09) is trying to determine the risk and return characteristics for three assets over the past five-year period of June 2004-2009. Two assets are for comparative purposes and these are the 13-week T-Bill (^IRX) interest rates and the S&P 500 (^SPSC) stock index. The third asset is Abbott Labs (ABT) common stock. Use the data provided in the Ex. 4.5 Worksheet of SS #2. Assuming each monthly return is equi-likely Finance Elective: MV Analysis 13 Jessica will determine the following return and risk measures for these three assets over the period given. a) Convert the T-Bill (percentage) rates into a decimal. Calculate the monthly returns for the S&P 500 Index and the Abbott Labs stock. b) Use the COUNT function to find the number of returns. c) Calculate the annualised Average percentage return using the function in (E4.1A). d) Calculate the annualised population Variance using the function given in (E4.2A). e) Calculate the annualised population Standard Deviation using the function given in (E4.3A). f) Calculate the Coefficients of Variation for each asset. g) Rank the assets on the basis of the risk-return tradeoff (where best trade-off is ranked 1). A4.5a) Convert T-Bill (%) rate to decimal by dividing by 100. Note: to have a number of returns that is consistent with the stocks ignore the first T-Bill rate. Sample Monthly Return (ABT 6/1/2004-7/1/2004) $34.83 1 = _______. R6/04 – 7/04 = $ 35 . 85 Excel Eqn.(H9): =(G9/G8)-1 Finance Elective: MV Analysis 14 A4.5b) There are 61 months of data so there are 60 monthly returns (for ABT). Excel Eqn.(H70): =COUNT(H$9:H$68) A4.5c) Annualised Average (for ABT), (E4.1A) is as follows: Excel Eqn.(H71): =AVERAGE(H$9:H$68)*12 For T-Bill: Excel Eqn.(D71): =AVERAGE(D$8:D$68) A4.5d) Annualised population Variance (for ABT), (E4.2A) is as follows: Excel Eqn.(H72): =VARP(H$9:H$68)*12 For T-Bill: Excel Eqn.(D72): =VARP(D$8:D$68)/12 A4.5e) Annualised population Standard Deviation (for ABT), (E4.3A) is as follows: Excel Eqn.(H73): = STDEVP(H$9:H$68)*SQRT(12) For T-Bill: Excel Eqn.(D73): =STDEVP(D$8:D$68)/SQRT(12) A4.5f) Coefficient of Variation (for ABT), using (4.6) is as follows: 18.014% CVABT = = _________ ______. 7.506% Excel Eqn.(H74): = H73/H71 Finance Elective: MV Analysis 15 A4.5g) Rank Coefficients of Variation (closest to zero is best risk-return trade-off): Asset 13wk T-Bills S&P 500 Index Abbott Labs 7 8 9 10 11 … 64 65 66 67 68 69 70 71 72 73 74 75 76 77 B Date 6/1/2004 7/1/2004 8/2/2004 9/1/2004 … 2/2/2009 3/2/2009 4/1/2009 5/1/2009 6/1/2009 CV 0.5733 -5.0285 2.4000 C 13w T-Bill 1.30 1.41 1.57 1.67 … 0.25 0.20 0.12 0.13 0.17 D Decimal 0.0141 0.0157 0.0167 … 0.0025 0.0020 0.0012 0.0013 0.0017 COUNT AVERAGE VARP STDEVP Coef Varn Rank 60 2.890% 0.00002 0.478% 0.1655 1 E S&P 500 1140.84 1101.72 1104.24 1114.58 … 735.09 797.87 872.81 919.14 920.26 Rank 1 3 2 F %Chg -0.0343 0.0023 0.0094 … -0.1099 0.0854 0.0939 0.0531 0.0012 G ABT 35.85 34.83 36.91 37.50 … 46.91 47.27 41.85 45.06 48.02 60 -3.058% 0.0236 15.376% -5.0285 3 Will come back later to calculate BETA. H %Chg -0.0285 0.0597 0.0160 … -0.1462 0.0077 -0.1147 0.0767 0.0657 60 7.506% 0.0324 18.014% 2.4000 2 BETA 0.214046 III. Expected Return, Variance, Standard Deviation, Covariance and Correlation Coefficients for/between Individual Assets A. Expected Return: Covered above. B. Variance and Standard Deviation: Covered above. C. Covariance: The covariance between two assets measures the extent to which the asset prices (or Finance Elective: MV Analysis 16 returns) ____ ________, or covary. If the returns between two assets tend to rise and fall together their covariance is positive. Conversely, negative covariances imply that if one asset’s return is above its mean, the other asset’s return tends to be below its mean. A covariance of zero implies no systematic relationship between the returns of the two assets. The general formula is given in (4.7) below when the probabilities of each state are different. n Covij = ij = [(Ri i) * (Rj j) * Pri j ] , (4.7) i j 1 where Rj = the return on asset j, and j = the mean return for asset j. The formula when the probabilities of each state are assumed to be equi-likely, i.e., 1/n, is then given in (4.7’). n 1 Covij’ = ij = * (Ri i )(Rj j ) . n i 1 (4.7’) The covariance calculation is similar to that of variance except that instead of squaring each asset’s deviation from its mean (the demeaned return), the two demeaned returns are multiplied together. In fact, an asset’s covariance with itself equals its ________. Finance Elective: MV Analysis 17 The Excel function to find the covariance assumes equi-likely probabilities and is given in (E4.7). Again the values used in the calculation will (necessarily) be in the form of an ARRAY. =COVAR(array1,array2) (E4.7) D. Correlation Coefficient: The correlation coefficient is a measure, which like the covariance, describes how the returns on two assets are related to each other. However, unlike the covariance which could vary from - to +, it is scaled to vary between -1 and +1. The correlation coefficient is found by dividing the covariance by the product of the asset standard deviations as shown in (4.8) below. ij Correlation Coefficient = ij = . i * j (4.8) Again, when the probabilities are equi-likely, the Excel correlation function can be used. Its form is given in (E4.8) below. =CORREL(array1,array2) (E4.8) Knowledge of asset mean returns and standard deviations are useful when assessing an asset’s risk/return tradeoff characteristics. Pairwise covariances and correlations provide information on the Finance Elective: MV Analysis 18 potential diversification benefits which may be achieved when assets are combined into portfolios. For example, combining two assets that are perfectly positively correlated, i.e. ij = +1, would not be expected to yield diversification benefits. On the other hand, combining two assets which are perfectly negatively correlated (ij = -1), will yield the maximum benefits in risk reduction. As might be expected, most assets (of the same type, eg. all shares) in a given market are generally, positively correlated to at least some degree. However, when different types of assets in the same (domestic) market, for example, shares, bonds and property, or similar assets from different (international) markets are combined, significant diversification benefits are achievable. The following example is meant to illustrate the use of the preceding formulas and provide students with an introduction to these calculations. Ex. 4.6 As a financial analyst you have projected the probabilities of three possible future states of (economic) nature and the relevant returns for stocks Alpha and Beta in each state. These are given in the table below. Use the Ex.4.6_Ex.4.7 Worksheet in Spreadsheet #2 to determine the: a) Expected Mean Return for each Asset, and Finance Elective: MV Analysis 19 b) Deviation from the Mean in each state for both assets. c) Use these deviations to find the Variances for both assets, and the d) Standard Deviation for each share. e) Also calculate the Covariance between the two shares using the deviations from part b), and f) Find the Correlation Coefficient. State of Economy Probability Expansion 0.25 Slow Growth 0.45 Contraction 0.30 E(RAi) Alpha 15.0% 5.5% -3.0% E(RBi) Beta 1.0% 4.0% 8.0% A4.6. The answers are provided in the spreadsheet results shown below. A 9 10 11 12 13 14 15 16 17 18 19 20 B State of Economy Expansion Slow Growth Contraction C Probability 0.25 0.45 0.30 Mean Variance Stnd Devn D E(Rtn) Alpha 15.0% 5.5% -3.0% E E(Rtn) Beta 1.0% 4.0% 8.0% 5.3250% 0.0044207 6.649% 4.4500% 0.000685 2.617% -0.001725 -0.991251 Covariance CorrCoef Some sample calculations are shown below: Finance Elective: MV Analysis 20 F G RA - A 0.09675 0.00175 -0.08325 RB - B -0.03450 -0.00450 0.03550 A4.6a) E(RA) = (.25*.15)+(.45*.055)+(.30*-.03) = ______. Excel Eqn.(D15): =($C11*D11)+($C12*D12)+($C13*D13) A4.6b) Deviations are shown in the spreadsheet above. Excel Eqn.(F11): =D11-$D$15 A4.6c) σ2(RA) = [(0.15 – 0.05325)2 * (.25)] ( = 0.0023401) + [(0.055 - 0.05325)2 * (.45)] ( = 0.0000014) + [(-0.03 - 0.05325)2 * (.30)] ( = 0.0020792) = 0.0044207 ( = 0.0044207) Note: I realize that you are all capable of doing this calculation in one go (step), using your calculator, using the parentheses as necessary. However, as a practical matter I would suggest that you do each of the three (grouped) calculations separately, as I have shown them above. The problem with a one-step approach is (very obviously) that if you make a mistake and do not see it, you will end up with the wrong answer. Further, you will not know where the calculation has gone wrong and cannot check it without doing the whole calculation again. Excel Eqn.(D16): =((F11^2)*$C$11)+((F12^2)*$C$12)+((F13^2)*$C$13) A4.6d) σ(RA) = 0.0044207 = _________ = ______. A4.6e) σAB = [(0.15-0.05325)*(0.01-0.0445)*(0.25)] + [(0.055-0.05325)*(0.04-0.0445)*(0.45)] + [(-0.03-0.05325)*(0.08-0.0445)*(0.30)] = (-0.0008345)+(-0.0000035)+(-0.0008866) = ___________. Finance Elective: MV Analysis 21 Excel Eqn.(E19): =(F11*G11*C11)+(F12*G12*C12)+(F13*G13*C13) σ 0.0017246 A4.6f) ρAB = AB = = ________. 0 . 06649 * 0 . 02617 σ * σ A B Excel Eqn.(E20): =E19/(D17*E17) IV. Calculating Markowitz Portfolio Return, Variance and Standard Deviation A. Portfolio Expected Return In general, portfolio E(Rp) is calculated by weighting the E(Ri)'s of the portfolio's component securities by the percentage of total portfolio market value for which they account. As a practical matter, the issue of how to appropriately calculate the weights is rather important from an investor’s viewpoint. <EXPLAIN> The general equation is: E(Rp) = where: E(Ri) wi N N [wi * E(Ri)], i 1 = expected return on asset i, = market value proportion of portfolio's total market value for which security i accounts, and = total number of securities in portfolio. B. Portfolio Variance and Standard Deviation Finance Elective: MV Analysis (4.9) 22 Unfortunately, calculation of portfolio variance (and standard deviation) is not quite as simple as before because ___________ between securities must also be taken into account. The general formula for the Markowitz variance of a portfolio is: N N Var(Rp) = wi * wj * ij , i 1 j1 where: wj ij (4.10) = proportion invested in security j, and = covariance between assets i and j. Recall from statistics that covariance may also be found given knowledge of the correlation coefficient as: ij = ij i j, (4.11) and also that the covariance of any asset with itself is equal to its ________. In long-hand, the Markowitz variance for a two-asset portfolio is Var(R2Ap) = (wi2i2) + (2wiwjij)+ (wj2j2). (4.12) With a three-asset portfolio, there are three variances and three covariances, so that this Markowitz portfolio variance has six terms. Finance Elective: MV Analysis 23 Var(R3Ap) = (wa2a2) + (2wawbab) + (2wawcac) + (wb2b2) + (2wbwcbc) + (wc2c2). (4.13) Beyond three assets, the variance calculation gets to be complicated fairly quickly. With four assets, there are four variance terms and six covariance terms (10 total). With five assets there are five variances and ten covariance terms (15 total). In fact, a ten-asset portfolio variance (10 variance terms and 45 covariance terms) is the largest that can be calculated in a single cell using Excel. F.Y.I., the formula to find the total number of terms equals [[(N*(N-1))/2]+N]. Ex. 4.7 Assume that on January 4, 1982, Mr. John Ross Ewing, Jr. (more popularly known as J.R.), President of Ewing Oil Company made an investment of approximately $10,000 in a three-asset stock portfolio to accumulate tuition money for his son John Ross’s college education at the University of Texas. Today is now July 1, 1997 and J.R. has you assigned you (as a financial analyst at Ewing Oil) the task of evaluating the portfolio’s investment performance. Because J.R. is aware of the benefits of portfolio diversification the three stocks he had chosen for investment are all in different industries, and are unrelated to the oil business. Namely, he has chosen Aetna Insurance (AET), Boeing Co. (BA) and ColgatePalmolive Co. (CL). The number of shares initially Finance Elective: MV Analysis 24 purchased as well as the initial prices for each stock are given as follows. Name Aetna Boeing Colgate #Shares 2250 1500 2500 Initial $2.38 $1.83 $0.50 Use the format given in the Ex.4.6_Ex. 4.7 Worksheet of Spreadsheet #2 as well as the monthly price data provided to determine the items below. Note, comparative data for the S&P 500 Index (^GSPC) is also provided. For Individual Assets: a) Geometric, monthly (unannualised holding period return (HPRM), and the monthly-annualised HPR (HPRMA) for each asset; b) Use the COUNT function to determine the number of monthly returns and convert it to years; c) Geometric HPR (annualised over the entire period) from 1/4/1982 to 7/1/1997 for each asset; d) Arithmetic mean return using both monthly HPRs then annualised (termed Mean(MonAnn)), and the monthlyannualised HPRs (termed Mean(AnnMon)), for each asset; e) Annualised (population) variances for each asset, using the: i) monthly returns, annualised; and ii) annualised monthly returns. f) Annualised (population) HPR standard deviations for each asset, using the: i) monthly returns, annualised; and Finance Elective: MV Analysis 25 ii) annualised monthly returns. g) Asset coefficients of variation using geometric mean as the return measure. h) Pairwise covariances (Annualised) between the three assets using the monthly HPRs. i) Correlation coefficients (Annualised) between the three assets using the monthly HPRs. For the Three-Asset Portfolio j) Calculate the beginning market value of the portfolio on 1/4/1982 and then the ending value on 7/1/1997. k) The portfolio’s geometric, annualised return based on ending, versus beginning total portfolio market value. Note: use the value for “t” previously determined in b) in the annualisation factor. l) The market value weights based on Beginning-ofperiod weights (BOP)w (use ROUND fn to 5 places); m) The Market-Value Weighted, Portfolio Mean Return using Asset Geometric Returns (w/ BOP weights); n) The three-asset Markowitz portfolio variance (w/ BOP weights); o) The Markowitz portfolio standard deviation; p) The weighted-average portfolio standard deviation (under the assumption that all assets are perfectly, positively correlated); and q) What can you conclude about the diversification benefits from the combination of three assets with correlations that are positive, but are relatively close to zero? Finance Elective: MV Analysis 26 r) The portfolio coefficient of variation. How does the portfolio CV compare to the individual asset CVs as well as the CV for the SPX? Finance Elective: MV Analysis 27 S 1 T U V ^GSPC W X Y Aetna Z AA AB Boeing AC AD AE Colgate 2 3 Date 1/4/1982 Adj Close 120.40 %Chg - AnnChg - Adj Close %Chg - AnnChg - Adj Close 1.83 %Chg - AnnChg - Adj Close 2.38 0.50 %Chg - AnnChg - 4 2/1/1982 113.11 -0.0605 -0.7266 2.34 -0.0168 -0.2017 1.62 -0.1148 -1.3770 0.52 0.0400 0.4800 5 3/1/1982 111.96 -0.0102 -0.1220 2.36 0.0085 0.1026 1.51 -0.0679 -0.8148 0.53 0.0192 0.2308 6 4/1/1982 116.44 0.0400 0.4802 2.22 -0.0593 -0.7119 1.65 0.0927 1.1126 0.56 0.0566 0.6792 … … … … … … … … … … … … … … 186 4/1/1997 801.34 0.0584 0.7009 10.88 0.0635 0.7625 42.12 0.0000 0.0000 22.74 0.1257 1.5089 187 5/1/1997 848.28 0.0586 0.7029 12.06 0.1085 1.3015 45.13 0.0715 0.8575 25.40 0.1170 1.4037 188 6/2/1997 885.14 0.0435 0.5214 12.22 0.0133 0.1592 45.45 0.0071 0.0851 26.73 0.0524 0.6283 189 7/1/1997 954.31 0.0781 0.9377 13.63 0.1154 1.3846 50.27 0.1061 1.2726 31.27 0.1698 2.0382 190 191 192 Count/12 193 GeomMn 194 ArithMn 195 Variance 196 StdDevn 197 CoefVarn ^GSPC Aetna Boeing Colgate 15.5 14.29% 14.49% 0.02090 14.46% 1.0118 15.5 11.92% 14.39% 0.06182 24.86% 2.0862 15.5 23.83% 25.60% 0.08556 29.25% 1.2275 15.5 30.58% 29.23% 0.04551 21.33% 0.6976 14.49% 0.02090 14.46% 14.39% 0.06182 24.86% 25.60% 0.08556 29.25% 198 199 VAR/COV ^GSPC Aetna Boeing Colgate CORRELS ^GSPC Aetna Boeing Colgate 200 ^GSPC 0.02090 0.58383 1.00000 202 Boeing 0.58488 0.29555 1.00000 203 Colgate 0.01916 0.01657 0.02024 0.04551 1.00000 Aetna 0.02476 0.02150 0.08557 ^GSPC 201 0.02099 0.06182 0.62102 0.31235 0.32441 1.00000 Finance Elective: MV Analysis Aetna Boeing Colgate 28 29.23% 0.04551 21.33% 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 J K L Name AET BA CL Initial #Shares 2250 1500 2500 1/4/1982 Initial $2.38 $1.83 $0.50 Wtd Price M O Initial Weights 0.57273 0.29358 0.13369 1.00000 MV $5,355.00 $2,745.00 $1,250.00 $9,350.00 $1.97 Portfolio Return Corr Coefs 0.2956 A&B 0.3124 A&C 0.3244 B&C N 7/1/1997 Reverse $13.63 $50.27 $31.27 Wtd Price Geometric 21.205% 3 ASSET MEAN (R3A) AET BA CL Variance/Covariance Matrix Aetna Boeing Colgate 0.06182 0.02149 0.01657 0.02149 0.08556 0.02024 0.01657 0.02024 0.04551 AET BA CL Matrix of Weights Boeing Colgate 0.16814 0.07657 0.08619 0.03925 0.03925 0.01787 Aetna 0.32802 0.16814 0.07657 MRKWTZ 0.039819447 ST DEV MRKWTZ 25.679% PORTFOLIO COEF of VARN ASSET Coef of Variations 3 ASSET PORT VAR 2(R3A) 17.910% WGHTD AVERAGE 3 ASSET MV $30,667.50 $75,405.00 $78,175.00 $184,247.50 $36.11 Wtd Price Geometric 20.652% 3-A Portfolio Variance (Matrix Multiplication) PORT P 3 ASSET PORT ST DV (R3A) 3 ASSET AET BA CL ^GSPC 29 0.039819 1.1142 2.0862 1.2275 0.6976 1.0118 19.955% Q Reversal Weights 0.16645 0.40926 0.42429 1.00000 A4.7. Two excerpts from Spreadsheet #2 are shown above. Note: The individual asset solutions and sample calculations apply to the SPX (the Standard & Poor’s 500 Index) data. For Individual Assets: P P 113.11 120.40 A4.7a) HPRM(SPX) = 1 0 = 120.40 P0 = ___________. Excel Eqn.(U4): =(T4-T3)/T3 HPRMA = HPRM * 12 = -0.06054817 * 12 = ___________. Excel Eqn.(V4): =U4*12 A4.7b) Using the COUNT function to find the number of returns there are 187 prices (15 years and 7 months), there are 186 monthly price changes. Thus, 186 converted to years would be (186/12=) 15.5 years. Excel Eqn.(U192): =(COUNT(U4:U189))/12 A4.7c) Geometric, annualised HPR from 1/4/82 to 7/1/97: P HPRG = t P0 1 t 1 954.31 15.5 1 = 120.40 30 1 = __________ = ________. Excel Eqn.(U193): =(T189/T3)^(1/U192)-1 A4.7d) Arithmetic Mean Monthly (Annualised) HPR: n Ri i 2.2460412 *12 Mean(MonAnn) = 1 *12 = 186 n = __________ = ______. Excel Eqn.(U194): =AVERAGE(U4:U189)*12 Arithmetic Mean Monthly-Annualised HPR: n (R * 12 ) i 1 i 26.9524940 Mean(AnnMon) = = 186 n = __________ = ______. Excel Eqn.(V194): =AVERAGE(V4:V189) A4.7e) Annualised (population) HPR Variance i) Monthly returns, annualised VARP: 31 n (R μ ) 2 i i *12 = _________. VARP Mon. HPR (Ann) = i 1 n Excel Eqn.(U195): =VARP(U4:U189)*12 ii) Annualised monthly returns VARP: n 2 (12 * R 12 * μ ) i i i 1 VARP Ann.-Mon. HPR = /12 n = _________. Excel Eqn.(V195): =VARP(V4:V189)/12 A4.7f) Annualised (population) HPR Standard Deviations i) Monthly returns, annualised STDEVP: STDEVP Mon. HPR (Ann) = n 2 (R μ ) i i i 1 * 12 n = _________. Excel Eqn.(U196): =STDEVP(U4:U189)*(12^0.5) ii) Annualised monthly returns STDEVP: 32 STDEVP Ann. = Mon. HPR n (12 * R 12 * μ ) 2 i i i 1 / 12 n = _________. Excel Eqn.(V196): =STDEVP(V4:V189)/(12^0.5) A4.7g) Coefficients of Variation based on Geometric Means: STDEVP 14.45781% CVSPX = = 14.2889% = ______. HPR G Excel Eqn.(U197): =U196/U193 A4.7h) Covariances (annualised) based on the monthly returns: n (R μ ) * (R μ ) i i j j i j1 * 12 = ________. σSPX,AET = n Excel Eqn.(U200): =COVAR($U4:$U189,X4:X189)*12 A4.7i) Correlation coefficients (annualised) based on the monthly returns; Note, as shown in the two formulations given below, to calculate the 33 correlations the CORREL function does not actually need to be based on annualised data. σ ij σ ij *12 ρSPX,AET = = (σ * σ ) (σ * 12 ) * (σ * 12 ) i i j j = _________. Excel Eqn.(AB200): =CORREL($U$4:$U$189,X4:X189) For the Three-Asset Portfolio: A4.7j) Beginning Market Value of the Portfolio: 1/4/1982: Name AET BA CL #Shares 2250 * 1500 * 2500 * Initial Price $2.38 = $1.83 = $0.50 = MV $5,355.00 $2,745.00 $1,250.00 $9,350.00 Ending Market Value of the Portfolio: 7/1/1997: Name AET BA CL #Shares 2250 * 1500 * 2500 * Initial Price $13.63 = $50.27 = $31.27 = MV $30,667.50 $75,405.00 $78,175.00 $184,247.50 A4.7k) The (geometrically annualised) Portfolio Holding Period Return: $184,247.50 Port HPRG = $9,350.00 1 15.5 34 1 = ________ = _______. Excel Eqn.(N19): =(P15/M15)^(1/U192)-1 A4.7l) To find the beginning-of-the-period (BOP) weights we need to first determine the initial market value (MV) of each position and then the initial MV of the portfolio: $5,355.00 (BOP)wAET = = _________ _______. $9,350.00 Excel Eqn.(N12): =ROUND(M12/$M$15,5) A4.7m) MV Wtd 3-Asset Mean Portfolio Return, μ(R3A) using equation (3.3) written out: μ(R3A) = (0.57273*0.1192)+(0.29358*0.2383)+(0.13369*0.3058) = ________. Excel Eqn.(L36): =(N12*X193)+(N13*AA193)+(N14*AD193) A4.7n) The 3-asset variance equation (3.7) written out with the specific notation for these three particular assets is shown below: 2 (R3A) = (w2AET2AET) + (2wAETwBAAET,BA) + (2wAETwCLAET,CL) + (w2BA2BA) + (2wBAwCLBA,CL) + (w2CL2CL). Here: 35 2(R3A) = (.57273)2*(.06182) + (2*(.57273)*(.29358)*(.02149)) <0.020278175> <0.007226746> + (2*(.57273)*(.13369)*(.01657)) + (.29358)2*(.08556) <0.002537473> <0.007374349> + (2*(.29358)*(.13369)*(.02024)) + (.13369)2*(.04551) <0.001588788> <0.000813401> = 0.039818932. Excel Eqn.(P36): =(N12^2*N23)+(2*N12*N13*O23) +(2*N12*N14*P23)+(N13^2*O24) +(2*N13*N14*P24)+(N14^2*P25) A4.7o) (R3A) = 0.039818932 = __________ = _______. Excel Eqn.(P39): =(P36^0.5) A4.7p) The average standard deviation (WA-SD) is essentially calculated just like the market-value, weighted portfolio return except that the asset standard deviations replace the asset returns. Prior to Markowitz, this approach was used to find portfolio standard deviation. It will always overstate portfolio SD whenever the assets being combined are not all perfectly positively correlated. WA-SD = (wAET*σAET)+(wBA*σBA)+(wCL*σCL). 36 WA-SD = (0.57273 * 0.2486) + (0.29358 * 0.2925) + (0.13369 * 0.2133) = _______. Excel Eqn.(L39): =(X196*N12)+(AA196*N13)+(AD196*N14) A4.7q) The correlation coefficients between the three assets (shown in cells L23:L25) are all positive and range from 0.2956 up to 0.3244. Thus, we would expect marked diversification benefits. Indeed comparison of the Markowitz standard deviation to the WA S-D shows the Markowitz SD to be 28.68% lower [(19.955-25.679)/19.955]. This difference is due totally to diversification benefits. σ(R 3A ) 0.19955 A4.7r) CV3-APort = = = ________. μ(R 3A ) 0.1791 Excel Eqn.(O41): =P39/L36 CVAET CVBA CVCL CVSPX = 2.0862; = 1.2275; = 0.6976; = 1.0118. The CV for Colgate is the only individual asset that yields a better risk-return trade-off compared to the portfolio although the SPX (a well-diversified portfolio containing 500 stocks) does too. Indeed this three-asset portfolio nearly has a CV that is as low as the SPX. 37 PRINCIPAL INVESTMENT RISKS GLOASSARY2 Active Management Risk: A fund may underperform because of the portfolio manager’s allocation decisions or individual security selections. Asset Allocation Risk: A fund may not maintain its target asset allocations. There is also the risk that those allocations may not achieve the desired risk-return characteristic or that the selection of underlying funds and/or the allocations among them will cause a fund to underperform similar funds or lose money. Call Risk: During periods of falling interest rates, an issuer may call (or repay) a fixed-income security prior to maturity, resulting in a decline in a fund’s income. Company Risk: The financial condition of a company may deteriorate, causing a decline in the value of the securities it issues. Credit Risk: The issuers of individual securities may default. Current Income Risk: The income a fund receives may fall as a result of a decline in interest rates. Derivatives Risk: A fund’s use of futures and options, and more complex derivatives such as swaps, may present liquidity, credit and counterparty problems. The risks associated with derivatives may be different and greater than the risks associated with directly investing in the underlying securities and other instruments. Downgrade Risk: A security may lose value because its rating is downgraded. Emerging Markets Risk: The risk of foreign investment may increase in countries with emerging markets where there is greater potential for political, currency and economic volatility. Securities issued in emerging market nations may be less liquid than those issued in more developed economies. Enhanced Index Risk: A fund may underperform its benchmark index due to differences between the fund and the benchmark index. Interest Rate Risk: Increases in interest rates can cause the price of fixed-income securities to decline. Large-Cap Risk: Large companies may grow more slowly than the overall market. Market Risk: The price of securities may fall in response to economic conditions. Market Volatility, Liquidity and Valuation Risk: Volatile trading activity may make it difficult for a fund to value its portfolio securities and the fund may not be able to purchase or sell a security at an attractive price, if at all. Mid-Cap Risk: The stocks of mid-capitalization companies may have greater price volatility, lower trading volume and less liquidity than the stocks of larger, more established companies. Mortgage Roll Risk: A fund’s managers may not correctly predict mortgage prepayments and interest rates, thus reducing fund return. Non-Investment-Grade Securities Risk: Non-investment-grade securities, which are usually called “high-yield” or “junk bonds” and whose issuers are typically in weak financial health and may be harder to value and sell. Prepayment Risk: The issuers of individual may prepay them at a time when interest rates have declined. Quantitative Analysis Risk: Stocks selected by the fund’s investment advisor using quantitative modelling and analysis could perform differently from the market as a whole. Real Estate Investing Risks: These are the various risks associated with the ownership of real estate including fluctuations in property values, higher expenses or lower income than expected, and potential environmental problems and liabilities. Extension Risk: The value of individual securities may decline because principal payments are not made as early as possible. Small-Cap Risk: Smaller company securities may be more volatile than those of larger ones. Securities of small-cap companies are often less liquid than securities of larger companies as a result of there being a smaller market for their securities. Foreign Investment Risk: Securities of foreign issuers may lose value because of erratic market conditions, economic and political instability, or fluctuations in currency exchange rates. This risk may be heightened in emerging or developing markets. Social Criteria Risk: Because a fund’s social criteria exclude securities of certain issuers for non-financial reasons the fund may forgo some market opportunities available to funds not using these criteria. Illiquid Securities Risk: Illiquid securities may be difficult to sell at their fair market value. Special Risks for Inflation-Indexed Bonds: Interest payments on, or market values of, inflation-indexed bonds may decline because of a change in inflation (or deflation) expectations. Income Volatility Risk: The income from a portfolio of securities may decline in certain interest rate environments. Index Risk: A fund’s performance may not match that of its benchmark index. Industry Concentration Risk: Because a fund’s investments are concentrated in a single industry, the value of its portfolio may fluctuate more and be subject to greater risk of loss than those of other funds. 2 Special Situation Risk: Stocks of companies involved in reorganizations, mergers and other special situations can involve more risk or display increased volatility than would ordinary securities. Style Risk: A fund’s investing style may lose favour in the marketplace. Underlying Fund Risk: A fund may invest in an underlying fund that fails to achieve its investment objectives. Source: 2010 Annual Review – TIAA-CREF Funds, September 30, 2010. 38