MEASURING INFORMATION ASYMMETRY IN LARGE ACTIVE FIRMS ON THE TEHRAN STOCK EXCHANGE

In financial markets, transparency of financial information is one of the most effective variables of investment strategies. Information asymmetry can seriously affect firm performance on the stock exchange and firms with a poor informational environment can lose the interest of investors. Reducing information asymmetry can have an important effect on firm performance on the stock exchange. Firms may lack a clear informational environment in the market because of the emerging conditions governing the Tehran Stock Exchange. Because larger and more active firms on the Tehran Stock Exchange provide more information, measuring the informational environment of these firms provides an overview of information asymmetry. The present study calculated the information asymmetry in these firms using the PIN and FE indices. The inconsistent results provided by these indices prompted the authors to offer a new index that is a composite of the PIN and FE that can better explain information asymmetry in developing market such as Asian stock markets. The results show that the new composite index, by using the mechanisms of the PIN and FE indices, provides a better outcome. The new composite index shows that the Tosee Melli Inv (TMEL1), Mobarakeh Steel (FOLD1), Iran Mobil Tele (HMRZ1), Saipa (SIPA1) and I.N.C. Ind. (MSMI1) firms have a better informational environment on the Tehran Stock Exchange.