This paper tests the effect of firms' mispricing and investment opportunities on the method of payment in mergers. Using a new proxy for investment opportunities and a sample of 1187 mergers completed between 1990 and 2005 among US publicly traded firms, I find that acquirers lead the decision on the method of payment, thus exploiting short-term market mispricing (in line with both the Rhodes-Kropf and Viswanathan, 2004 and Shleifer and Vishny, 2003 models). However, target managers believe in the quality of the merger and care about the long-term value of the merged entity's shares (as predicted by Rhodes-Kropf and Viswanathan, 2004 and contrary to Shleifer and Vishny, 2003). I also find that better investment opportunities lead to greater use of stock.