The investigation of overreaction and the effect of the short-term investment periods

purpose of this article is to examine the investors’ overreaction and the effect of the short?term periods. 152 companies listed in Tehran stock exchange were examined in period of 2007-2010. The findings show that ordinary shareholders do not show overreaction to the shares yield, sale and profit in Tehran Stock Exchange in short?term before unexpected items. So it is not possible to increase the shares yield by applying the reverse investment strategy instead of relative power strategy in buying and selling the shares by virtue of the variable. Also by virtue of the presented findings the ordinary shareholders show overreaction to the companies’ sale and cash flow in Tehran Stock Exchange.