Efficient market hypothesis is based on the idea that information is quickly and efficiently incorporated into asset prices at any point in time and consequently past prices cannot be used to predict future price movements since addition to existing information cannot be foreseen. In other words the current market price reflects all publically available information. Under the conditions the current market price in any financial market could be the best unbiased estimate of the value of the investment. The present study is an attempt to test the informational efficiency of the Indian stock market in the semi strong form of efficient market hypothesis with respect to event of bonus issue announced by listed on BSE 500 companies during the study period. In this study to test the stock price reaction to information content of bonus issues with a view of examining whether the Indian stock market is semi strong efficient. All AARs after the announcement day (except +3 day) are not statistically significant. It reveals that the investors are not earned AARs in the sample companies.
Key Words: Stock Market, Efficient Market Hypothesis, Bonus Issue, Event Study, AAR and CAAR.