This study introduces the development and modifications of the widely used standard capital asset pricing model (CAPM). Many modifications are applied to the model’s challenging financial variables such as: financial risk factors, liquidity risks, downside risks, risk of non expected events, and economic and operational risk factors. Efficiency of the model is increased when applying various challenging financial variables. As a result of the gradual CAPM developments, various new models will present better interpretations of market conditions in economic units and portfolio structure. Furthermore, this study will show the importance of applying the new models advantages and disadvantages for financial managers, financial analysts and investors.

This paper tried to analyze the performance of the investment companies listed in Tehran Stock Exchange that had active portfolio management from 2006 to 2010 by Sharp, Treynor, and Sortino ratios. For more profound study of their performances, this research used some of the measures, including turnover, liquidity, size and diversification of portfolio. After gathering needed test data and relevant statistical tests as Kolmogorov-Smirnov and Shapiro-Wilk, the results showed the distribution of data was not normal. Therefore, the hypothesis was tested by nonparametric tests. The results of the first hypothesis about the three mentioned above ratios and with Freidman and Wilcoxen tests showed the companies had better controls on systematic risk than other components. The result of the second hypothesis by using combined Anova and Multiple Anova showed portfolio turnover in the companies had positive and significant affect in the companies performances than other measures.It is possiblefor anyone to be able to find a company that has a high level of portfolio turnover and a high level of performance than other companies while it has a lower level of other measures.