Pré-publication, Document de travail: Two players receiving independent signals on a risky project with common value compete to be the first to invest. We characterize the equilibrium of this preemption game as the publicity of signals varies. Private signals create a winner's curse: the first mover suspects that his rival might have privately received adverse information, hence exited. To compensate, players seek more evidence supporting the project, resulting in later investment. A conservative planner concerned with avoiding unprofitable investments may then prefer private signals. Our results suggest that policy interventions should primarily tackle winner-takes-all competition, and regulate transparency only once competition is sufficiently mild.