Basically this is an empirical study which aims to test the Markowitz Modern portfolio theory (MPT) or the mean-variance analysis. Fund managers and general investors seek a portfolio that yields maximum return with minimum risk. The problem of investors is dual in nature, as Markowitz showed, i.e., the indifferent choice of risk and return. Though, diversification reduces non-systematic risk but due to limited resources one cannot afford to invest in all stocks, therefore it is pertinent to know that what should be the minimum level of stocks in a portfolio that produces maximum return and minimum risk. The theoretical framework of Markowitz MPT tested by computed 134 months expected the return of thirtytwo stocks, thirty-one variances and 465 co-variances, in order to evaluate efficient portfolio frontier.