Author(s): Ozan G├ľN├ťLL├ť
Companies aiming to grow encounter two choices to accomplish their objective. Companies which are required to make a choice between internal growth and external growth should assess the positive and negative aspects of both of the choices accurately and should form their growth strategies accordingly. Upon free capitalization which began early 1980s, company mergers which converted into a global structure has become an important external growth strategy worldwide. In this study, two separate points were researched; the impact of merger and acquisition on stock performance, and; whether the shareholder which keeps the share of the company- subject to merger- has obtained abnormal return or not due to this action. In the research, 163 merger and acquistion event were discussed, in which at least one of the companies subject to merger is the member of Borsa ?stanbul (with its previous name ?MKB), and based on Event Study method; the difference of returns of various companies which are acting in different fields were determined both prior and after the relevant announcement thereof. In order to test whether cumulative average abnormal returns prior to announcement date and cumulative average abnormal returns after the announcement date are different from each other meaningfully or not; with Paired Sample t-Test; in order to specify whether the partner which keeps the stock from the beginning up to the end of the event window can obtain abnormal return or not, One-Sample Test was used.