Market reaction to large bank merger announcements in oligopolies

This paper evaluates the individual and rival stock price reactions to large bank merger announcements and subsequent regulatory rejection in an oligopoly. The results show that the announcements produce significant positive abnormal returns for the merger candidates. Regulatory obstacles and denial of the proposed mergers produce significant negative returns. Analysis of the rivals’ reactions doesn’t produce consistent significant results. This suggests that the market reactions for the merging banks results are driven by expected increases in efficiencies. The rivals’ reaction is explained by the fact that the market would remain contestable after the mergers since the offered products are homogeneous.(JEL G14, G34)