شناسايي عوامل مؤثر بر بازده غير عادي سهام در زمان عرضه اوليه به عموم در شركت هاي پذيرفته شده بورس اوراق بهادار تهران

The Identification of Effective Factors on Abnormal Returns of Initial Public Offerings (IPOs) In Tehran Stock Exchange

An Initial Public Offering (IPO) occurs when a security is sold to the general public for the first time with expectation that a liquid market will develop. It is the means by which a firm first obtains a listing. Shares are sold to investors and the proceeds are invested by the firm. Sometimes a listing is obtained by an entrepreneur selling her or his shares to the public and the firm issues no new shares and therefore receives no proceeds .Although an IPO can be of any debt or equity security, this thesis will focus on equity issues. In this study the existence of abnormal return in initial public offering of Tehran Stock Exchange and its effective factors were examined. The results show that there is positive long term abnormal return during 12 and 24 month after the initial public offering of stocks in Tehran Stock exchange. Among nine variables; forecast error of earning per share, stock market return one month before the offering of stock, leverage, margin of profit, return on equity, Size, age, Horizon, Coefficient of Variances, only forecast error of earning per share (directly) and stock market return one month before the offering of stock and margin of profit (reversely) had a significant relationship with abnormal return in 12 month after the initial public offering of stocks. Also; any variable had not a relation with abnormal return in 24 month after the initial public offering of stocks. However, multi variable regression analyses demonstrated that all of the variables can simultaneously justify just around 42% of abnormal return during 12 month after the initial public offering of stocks in Tehran Stock exchange.