M.A. Thesis:

Theof informational asymmetry before positive and negativeearningssurprise and its comparing with the past investment plans disclosures.

Fast notification by companies is crucial to timely decision making by investors and shareholders, but there are many observations and evidence suggesting that companies would publish their company's news and information later or earlier in order to maintain their own interests. Which creates information asymmetry among users of financial statements, this phenomenon results in the transfer of capital unfairly to well-known and informed investors of corporate information. In this research, we investigate information asymmetry before unexpected positive and negative outcomes and compare it with previous disclosure of investment plans, to increase the level of information transparency of companies against financial users both when there is positive information and what Turn on negative information. To measure the asymmetry of information, indicators such as amiguity index and stock price changes and changes in stock turnover volume were used. In order to test the hypotheses, 124 firms were selected using a systematic elimination sampling from Tehran Stock Exchange (TSE), and the assumptions were tested using the two-way mean comparison method and the generalized least squares regression method The results of the assumptions show that among the Companies Listed in Tehran Stock Exchange, Positive news is more timely and faster than negative news; And as a result, users are informed and respond appropriately before releasing statements of unexpected positive profits. But prior to the release of unexpected negative earnings, there has been a lot of news coverage or a late release that has not received a good response from investors.

Keywords: Information Asymmetry, negative earnings surprisees, positive earnings surprisees