The Study of Effect companies information reports to Tehran Stock Market Daily Behavior

The existence of enough information on market and on time reflection of these information which affects securities prices, has very close relation with market efficiency. In such a market, distributed information affects securities prices and causes them to be more closes to their intrinsic value. This research, by choosing some events (such as General Assembly of shareholders, quarterly financial reports, predicting profit and announcing the real annual profit) and according to data obtained in 30 days around the event during the period between 2007 to 2011, investigates the reaction of stock market to events using paired T-Test and also compares it with efficient market model. Results show that stock market has a significant reaction to this information and also the market behavior toward these events is not efficient.