The effect of specific characteristics of companies on systematic risk in firms accepted in Tehran Stock Exchange

The goal of the present research is to study certain firm features including: firm size, firm growth, and financial leverage and their effect on systematic risk in firms enlisted in Tehran Stock Exchange. Regarding theoretical foundations and research literature, a regression model was devised and used to analyze data. The statistical sample for this research included 85 companies from among firms enlisted in Tehran Stock Exchange during the time period between 2001 and 2011. The research results showed that firm size has had a positive and meaningful effect on systematic risk, but firm growth and leverage did not have a meaningful effect on systematic risk; but by considering firm size as control variable, the effect of firm growth on systematic risk in small and big companies will become meaningful.