An investor has two stocks, Stock R and Stock S in her portfolio. Given the following information on the two stocks, the portfolio's standard deviation is closest to:
- σR = 34%
- σS = 16%
- rR,S = 0.67
- WR = 80%
- WS = 20%
The formula for the standard deviation of a 2-stock portfolio is:
s = [WA2sA2 + WB2sB2 + 2WAWBsAsBrA,B]1/2
s = [(0.82 × 0.342) + (0.22 × 0.162) + (2 × 0.8 × 0.2 × 0.34 × 0.16 × 0.67)]1/2 = [0.073984 + 0.001024 + 0.0116634]1/2 = 0.08667141/2 = 0.2944, or approximately 29.4%.
|