This thesis examines the performance of serial acquirers in the Nordic market between 2006-2016. We investigate how serial acquirers perform in the short-term and long-term and if serial acquirers are affected by hubris, or if they learn by experience. The payment method is examined to determine if cash-financed deals outperform equity-financed deals. The short-term performance study is measured by the Cumulative Abnormal Return (CAR) and the long-term performance study is measured by the Calendar-Time Portfolio (CTP) combined with the Fama-French Four-Factor model. The main findings show that serial acquirers underperform relative to single acquirers only in the short term. No significant results are found for the hubris and learning hypotheses. In addition, we find that acquirer size and the deal size have a significant effect on the short-term post-M&A performance.