The rapid increase in the number of mergers and acquisitions (M&As) from the 1990s onward can be attributed primarily to a type of shock to the growth and/or profitability of certain industries and corporations. Characteristics of industries and corporations subject to particularly aggressive M&A activities include higher growth opportunities, high profitability and lower debt ratios. In this regard, it is fair to say that M&As from the 1990s onward have been used by companies and industries with higher growth opportunities as a tool to turn these opportunities into reality.