This dissertation comprises three chapters about investor reactions to significant events and the growth strategy of large banks in the global financial crisis. The first chapter focuses on the subprime mortgage phase of the crisis. We examine whether investors significantly reacted to events until Lehman Brothers’ collapse. We use the event study methodology to calculate abnormal returns of large banks in the sample. We find that investors reacted significantly to the events. As the crisis approaches, investors’ reaction becomes more significant. Results suggest that Lehman Brothers’ collapse is not a cause but a result of the crisis. The second chapter investigates the effect of the growth strategy of large banks on investor reactions to significant events during the global financial crisis. We construct a growth index decomposing into the merger index and organic growth index. Using the event study methodology, we find abnormal returns of the large sample banks. Applying cross-sectional event-specific and pooled OLS regressions, we analyze cross-sectional variations of investor reactions to significant events. Results indicate that investors significantly reacted to the growth strategy of large banks after the Lehman Brothers’ collapse but not before. The third chapter examines investor reactions in Europe to major events until the Lehman Brothers’ collapse. We calculate the abnormal returns of fifty-four banks across sixteen countries in Europe with the event study methodology. Our findings show that investors react significantly to the events as the Lehman Brothers’ failure comes closer. Hence the Lehman Brothers’ bankruptcy is a major turning point during the crisis.