Imitation of first-mover firms in opting for a merger or acquisition (M&A) facilitates merger-wave formation. Empirical evidence suggests that, under uncertainty of outcomes, firms regret more not following their rivals’ strategy than possibly failing jointly by copying it. We explore the outcomes and look for underlying behavioral assumptions in that decision-making framework by modal logic. Biased expectations, represented by the B (belief) modal operator, filter out relevant scenarios from managerial consideration. The theorems highlight the drive to imitate first-mover M&As. Our approach goes against the view that human behavior, being non-logical in many respects, defies logic-based rendering. Logic is a flexible representation tool that can model even faulty behavior in a transparent way, also exploring the consequences of the cognitive mistakes made. Our findings suggest that threats to wealth creation may not necessarily find their origins in morally dubious organizational behavior, but rather in modalities of decision making under uncertainty.