I examine the motivation for, and effect of, including a collar in a merger agreement. The most important cross‐sectional determinants of the bid structure (cash vs. stock, and whether to include a collar) are the market‐related stock return standard deviations for the bidder and target. This evidence supports the hypothesis that the method of payment is dependent on the sensitivities of the bidder and target to market‐related risk because either has the incentive to demand renegotiation of the merger terms if the value of the bidder's offer changes materially relative to the value of the target during the bid period.

The monthly volatility of IPO initial returns is substantial, fluctuates dramatically over time, and is considerably larger during “hot” IPO markets. Consistent with IPO theory, the volatility of initial returns is higher for firms that are more difficult to value because of higher information asymmetry. Our findings highlight underwriters’ difficulty in valuing companies characterized by high uncertainty, and raise serious questions about the efficacy of the traditional firm‐commitment IPO process. One implication of our results is that alternate mechanisms, such as auctions, could be beneficial for firms that value price discovery over the auxiliary services provided by underwriters.