I define and analyze the agency costs of overvalued equity. They explain the dramatic increase in corporate scandals and value destruction in the last five years; costs that have totaled hundreds of billions of dollars. When a firm equity becomes substantially overvalued it sets in motion a set Of organizational forces that are extremely difficult to manage-forces that almost inevitably lead to destruction of part or all of the core value of the firm. WorldCom, Enron, Nortel, and eToys are only a few examples of what can happen when these forces go unmanaged. Because we currently have no simple solutions to the agency costs of overvalued equity this is a promising area for future research.