Corporate theory matters. By way of example, I explain in this Essay how Citizens United can be read as a decision wherein the competing theories of the corporation played a dispositive role. Furthermore, some of the most important issues confronting courts and legislatures in the foreseeable future will involve questions about the nature of the corporation. In light of this, this Essay argues that the Dodd-Frank Wall Street Reform and Consumer Protection Act serves, in addition to all its other roles, as an important and novel data point in the on-going corporate theory debate. Specifically, I argue Dodd-Frank implicates corporate theory in two ways. First, it reaffirms yet again that corporations remain subject to significant government regulation as a matter of positive law—a fact that constitutes at least somewhat of a nuisance for contractarians. Second, and more importantly, Dodd-Frank’s formal recognition that at least some corporations have literally gotten too big to fail vindicates some of the most important normative assertions of concession theory broadly defined.