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This study investigates the relationship between research and development costs and stock return. To test the research hypotheses Fama and Macbeth (1973) and Fama and French (1993) models are used. The sample of 27 manufacturing companies listed in Tehran Stock Exchange for a time period of 2003 to 2011 is selected. Statistical multiple regression model is used for data analysis. Results indicate that between research and development costs and stock return a significant relationship does not exist. Moreover between research and development costs and risk premium in risk covering portfolio a significant relationship is not found

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The net profit of any business entity for a particular time period can be conceptualized as the final outcome of its investing, financing and operating activities. These activities are influenced by Management’s decisions and several internal and external environmental factors. This paper investigates how profitability of firms, for 125 public limited companies listed at Tehran Stock Exchange for a period of 2006-2013, is influenced by working capital management and capital structure of firms. The dependent variable is Earning before Interest and Taxes (EBIT) as a measure of profitability. The independent variable are current ratio (as representative of the result of working capital management policy) and financial leverage (as the bench mark for capital structure). Supplementary variable were also undertaken to assess the impact of operating leverage and firm size on profitability. The regression results show that negative relationship between the Profitability measures of firms and Current Ratio and a posetive relationship between the profitability measures of firms and degree of Financial Leverage.