# portfolio variance

• October 22nd 2009, 07:00 AM
pinkiee
portfolio variance
suppose that we live in an N-asset world. how do i show that the portfolio variance of an equally-weighted portfolio is:

$var(Rp)= 1/N^2 sum_{i=1} (cov(i,j)) + 1/N^2 (sum) (sum) cov(i,j)$