Examining the Effect Of Product Market Competition and Return Momentum on Cost of Equity Capital of Companies Listed in Tehran Stock Exchang

The cost of capital is one of the most important and significant feature in many financial decisions and management. It also has the high value for the managers of companies and affects on several factors such as financial leverage, profitability, shareholders combination , composition of the board, company's activities, liquidity and size. Inspite of the fact that the ability of fundraising and financial providing of companies is the most important factors to remain in the current market competition, so this study examines the effect of product market competition and return momentum on the cost of capital of Companies listed in Tehran Stock Exchange over 2009-2014 .To do so, Excel and Eviews softwares were used in this research. Also, Herfindahl-Hirschman index is used to measure Product market competition return momentum. The results show that Product market competition has negatively significant effect on the cost of capital of Companies listed in Tehran Stock Exchange. However, there is no significant relationship between return momentum and the cost of capital.