03 December 2010
Hi.., in simple terms, Beta is considered as a factor representing change in the return of security directly related to change in the market... For example, if B=0.7%., that means, wid every 1% change in market (whether up or down), return on security too will change in same direction by 0.7%...... A portfolio consists various securities, that means, portfolio return is consisted of such individual security returns... Now, equal wieghts cannot b allotted as amount invested in each security is different.., on such investments based, weights r allotted.... Thus, while calculating portfolio beta, we calculate weighted average to avoid miscalculations....
03 December 2010
Lets take an example.., in figures u gave, as per weightage avverage, we get portfolio beta as 0.95.... But if v dnt take weightage avg., rather we consider as simple average, we get portfolio beta as 1, which is not correct..... I wud suggest u to take practical example of investing rs 2000 in A, 1000 in B and 1000 in C.... An solve this problem by both methods, i.e simple average and weightage average....