Even though self-fulfilling currency attacks lead to multiple equilibria when fundamentals are common knowledge, the authors demonstrate the uniqueness of equilibrium when speculators face a small amount of noise in their signals about the fundamentals. This unique equilibrium depends not only on the fundamentals but also on financial variables, such as the quantity of hot money in circulation and the costs of speculative trading. In contrast to multiple equilibrium models, the authors' model allows analysis of policy proposals directed at curtailing currency attacks.