Respuesta :
Answer:
The standard deviation of a two asset portfolio with a correlation coefficient of .35 will be lower than the weighted average standard deviation of the portfolio
Explanation:
The bone of contention here is whether the standard deviation formula for a two-asset portfolio produces a higher, equal, or lower standard deviation compared to the weighted average standard deviation of the portfolio when the correlation between the two assets is 0.35.
Let us assume random numbers:
σP = √(wA2 * σA2 + wB2 * σB2 + 2 * wA * wB * σA * σB * ρAB)
wA=proportion of the portfolio invested A=45%
σA=standard deviation of return of A=15%
wB=proportion of the portfolio invested B=55%
σB=standard deviation of return of B=20%
ρAB= correlation between both= 0.35
square root=^(1/2)
Note the formula above without the square root gives variance of the portfolio
standard deviation
=(45%^2*15%^2+55%^2*20%^2+2*45%*55%*15%*20%*0.35)^(1/2)
standard deviation= 14.78%
weighted average standard deviation of the portfolio=(45%*15%)+(55%*20%)
the weighted average standard deviation of the portfolio=17.75%
The standard deviation using the two-asset formula is lower