We study the efficiency of premarital investments when parents care about their child’s marriage prospects, in a large frictionless marriage market with nontransferable utility. Stochastic returns to investment ensure that equilibrium is unique. We find that, generically, investments exceed the Pareto-efficient level, unless the sexes are symmetric in all respects. Girls will invest more than boys if their quality shocks are less variable than shocks for boys or if they are the abundant sex. The unique equilibrium in our continuum agent model is the limit of the equilibria of finite models, as the number of agents tends to infinity.