Portfolio Management

Portfolio management is based upon the old saying that one should not keep all the eggs in the same basket. You refer here Markowitz mean variance portolio creation criteria to diversify the risk which is also known as Modern Portfolio theory.CAPM is further advanced this issue by bringing Beta is portolio selection criteria.

In nutshell Portfio management look at the basket of securities in stead of each secutities and try to optimise the gain by diversifying risk.