The Information Content of Covid 19 Outbreak Announcement in Tehran Stock Exchange

Investing in the stock market undoubtedly is a vital part of the economy of the whole country, and the national economy is heavily influenced by stock market performance. Therefore, it is very important to study and identify the factors affecting stock returns for managers and investors. This study was conducted aimed to examine the information content of announcing the news on the coronavirus disease (COVID-19) outbreak in the Tehran's stock market. This study is considered as an applied research in terms of purpose and event study in terms of nature. In this study, the data was collected through the CODAL and TSETMC websites and the statistical sample includes all companies listed in the Tehran Stock Exchange in 2019. Temporal scope of the research was a week before and after the announcement of the coronavirus disease (COVID-19) outbreak in the world and a week before and after announcing the news on the coronavirus disease (COVID-19) outbreak in Iran. Sampling was done systematically and the sample size for two time periods was considered 407 and 375 companies, respectively. Data were analyzed by Means-test. According to the results, the announcing the news on the coronavirus disease (COVID-19) outbreak in the world and Iran did not have abnormal returns among sample companies, nor was there a significant difference between the returns of large and small companies.