The effect of M&A announcement on Greek bank stock returns

This study examines the response of Greek bank stock prices to the announcement of intended mergers and acquisitions(M&As)during the period 1998-1999, applying a standard event study methodology. The results show that both the acquiring banks and, albeit to a lesser extent, the target banks experience significant positive abnormal stock returns that last for a few days around the announcement date. These returns are more evident in the period before the announcement thus indicating either that rumours circulate or that inside information is being abused. The efficient market hypothesis in its semi-strong form seems to be violated for the period under examination, as abnormal returns remain evident for several days after the announcement date.