Asset A has an expected return of 10% and standard deviation of 20%. Asset B has
ID: 2778470 • Letter: A
Question
Asset A has an expected return of 10% and standard deviation of 20%. Asset B has an expected return of 16% and a standard deviaiton of 40%. The correlation between A and B is 0.35. Portfolio C is composed of 30% asset A and 70% asset B.
Portfolio C: Expected return= 14.2% Standard deviaiton= 30.62%
Question:
A)Plot the attainable portfolios for a correlation of 0.35. Now plot the attainable portfolios for correlatio of +1.0 and -1.0.
B) Suppose a risk-free rate has an exdpected return of 5%. By definiton, its standard deviation is zero, and its correlation with another asset is also zero. Using only asset Aand the risk-free asset, plot the attainable portfolios.
Explanation / Answer
Attainable portfolio at correlation 1 is
Expected return = weight of asset A * expected return on asset A + weight on asset B * expected return on asset B
= 0.30*10+0.70*16
= 14.2%
Standard deviation of portfolio at correlation of +1
= [(Weight of A)^2* (SD of A)^2 + (Weight of B)^2 * (sd of B)^2 +( 2 * Correlation coefficient * weight of A* weight of B * SD of A * SD of B)]^1/2
= (0.30^2)(20^2) + (0.70^2)(40^2) + 2*1 *0.30*0.7*20*40
= [36+784+336]^1/2
=34%
The portfolio will have same return of 14.2% and standard deviation of 34% at correlation of +1
When correlation is -1
The return remains same
The Standard deviation changes
= [(Wa^2)(SD of A^^2) +(Wb ^2)(SD of B ^2) +2 * -1* Wa Wb* SD of A * SD of B]^1/2
=(0.3^2)(20)^2 + (0.70^2)(40^2) + 2*-1*0.30*0.70*20*40
= 36+784-336
=(484)^1/2
= 22%
When risk free asset is used
Expected return = 0.30*10+.70*5
= 6.5%
Since , risk free asset does not have any risk of its own,
The portfolio will only have risk of it risky asset
= weight of A * SD of A
= 0.30* 20 =6%