TY - JOUR AB - Purpose– Researchers suspect that the overvaluation of equity issuing acquirers is a major cause of their subsequent post-event underperformance. Definitive conclusions regarding this overpricing hypothesis have not been possible since indicators of overpricing such as the book-to-market ratio and subsequent underperformance are open to alternative interpretations. The purpose of this paper is to corroborate or refute overvaluation as a driver of equity issuing acquirers’ subsequent underperformance. Design/methodology/approach– The literature has linked overvaluation of acquirers to over-optimistic expectations. The authors use analysts’ earnings forecasts to reflect the market's expectations. Over-optimism is indicated by subsequent earnings disappointments. The authors examine the relation between acquirers’ choice of payment method and their tendency to report disappointing earnings. The authors also examine the effect of including a more direct measure of over-optimism in a model to explain the long-run post-event buy-and-hold-abnormal returns of acquirers. Findings– The post-acquisition earnings of equity issuing acquirers disappoint more often than those of acquirers employing alternative financing methods. This relationship is confined to glamour acquirers. The ability of financing method to predict long-run post-acquisition performance is subsumed when direct measures of optimism are included in a model explaining long-run post-acquisition performance. This result is robust to controls for overpayment and other potential explanations of post-acquisition underperformance. Research limitations/implications– Acquirers’ management exploit their information advantage to exchange overvalued equity for the assets of the target company in accordance with Loughran and Ritter's (2000) behavioural timing hypothesis. Originality/value– The study provides new and unambiguous evidence that equity-issuing acquirers are optimistically priced at the time of acquisition. VL - 10 IS - 4 SN - 1743-9132 DO - 10.1108/IJMF-01-2012-0001 UR - https://doi.org/10.1108/IJMF-01-2012-0001 AU - Donnelly Ray AU - Hajbaba Amir PY - 2014 Y1 - 2014/01/01 TI - The acquisition puzzle and mispricing: evidence of over-optimism T2 - International Journal of Managerial Finance PB - Emerald Group Publishing Limited SP - 470 EP - 493 Y2 - 2024/04/25 ER -