This study focused on factors that have positively influenced the model of economic success for commercial and thrift megabanks involved in merger and acquisition activities for the period 1990 - 1997, a period characterized by an unprecedented flurry of merger and acquisition activities among megabanks in the United States. This study identified and measured key independent variables for identifiable mergers and acquisitions among megabanks and tested the extent to which, such independent variables influenced abnormal returns for underlying equities traded in capital markets. This study also tested the hypothesis that megabanks are attracting significantly higher acquisition premiums than the relatively smaller banks. The data collected and the conclusions drawn were based on the logic of a hypothetico-deductive paradigm, which essentially utilized the techniques of the standard event study methodology, and included parameters of the conventional Capital Asset Pricing Model. This study was based on a scientifically determined sample of over 200 banks in the small bank category and between 68 and 86 banks grouped under the megabank category. The findings revealed that megebank acquirers realized negative abnormal returns and that megabank acquirees did not realize economic value significantly greater than acquirers for those banks that integrated on a merger-of-equals basis. The findings also showed that megabanks seemed more willing to pay higher premiums for the right to integrate with other megabanks vis-a-vis the right to integrate with small banks.