A step toward a strategic foundation for rational expectations equilibrium is taken by considering a double auction with n buyers and m sellers with interdependent values and a ¢ liated private information. If there are su ¢ ciently many buyers and sellers, and their bids are restricted to a su ¢ ciently …ne discrete set of prices, then, generically, there is an equilibrium in nondecreasing bidding functions that is arbitrarily close to the unique fully revealing rational expectations equilibrium of the limit market with unrestricted bids and a continuum of agents. In particular, the large double auction equilibrium is almost e ¢ cient and almost fully aggregates the agents’information. 1.