Page 84 - DMGT207_MANAGEMENT_OF_FINANCES
P. 84

Unit 4: Risk and Return Analysis




          Return of portfolio (R )                                                              Notes
                            p
                            = (0.80 × 9) + (0.20 × 8) = 7.2 + 1.6 = 8.8%
          Risk of portfolio ( )
                          p
                                  2
                          σ 2 p  = (0.80  × 10.49 ) + (0.20  × 16.31 ) + (2 × 0.80 × 0.20 × 10.49 × 16.31 × 0.491)
                                               2
                                                      2
                                        2
                            = (0.64 × 110.04) + (0.04 × 266.02) + 26.88
                            = 70.43 + 10.64 + 26.88 = 107.95
                            =  107.95  = 10.39%
                           p
          4.7.3 Risk and Return of Portfolio (Three Assets)

          Formula for calculating risk of portfolio consisting three securities

                                2
                                            2
                                              2
                                        2
                                  2
                                      2
                         σ 2 p  =  W σ + W σ + W σ + 2W W ρ σ σ + W W ρ σ σ  z
                                            z
                                              z
                                                   x
                                        y
                                x
                                  x
                                      y
                                                     y
                                                                 z
                                                                   xz
                                                                     x
                                                               x
                                                       yz
                                                         y
                                                           z
          Where,
                   W , W , W  = Proportion of amount invested in securities X, Y and Z
                     1  2  3
                       ,  ,   = Standard deviations of securities X, Y and Z
                       x  y  z
                            = Correlation coefficient between securities X and Y
                           xy
                            = Correlation coefficient between securities Y and Z
                           yz
                            = Correlation coefficient between securities X and Z
                           xz
          Illustration 13: A portfolio consists of three securities P, Q and R with the following parameters:
                                                    Security               Correlation
                                                                           coefficient
                                             P          Q         R
             Expected return (%)            35          22        20
             Standard deviation (%)         20          26        24
             Correlation coefficient:
             PQ                                                               –0.5
             QR                                                               +0.4
             PR                                                               +0.6

          If the securities are equally weighted, how much is the risk and return of the portfolio of these
          three securities?
          Solution:
          Expected Portfolio Return
                            = (25 × 1/3) + (22 × 1/3) + (20 × 1/3) = 22.33%
                                                     2
                                      2
                                           2
                           2
                                                 2
                                 2
                          σ  = (30) (1/3) +(26) +(24) (1/3) + 2(1/3)(-0.5)(30)(26)
                           p
                                              + 2(1/3)(1/3)(0.4)(26)(24) + 2(1/3)(1/3)(0.6)(30)(24)
                           σ  2 p  = 100 + 75.11 + 64 – 86.67 + 55.47 + 96 = 303.91
                            =  303.91  = 17.43%
                           P
                                           LOVELY PROFESSIONAL UNIVERSITY                                   79
   79   80   81   82   83   84   85   86   87   88   89