Currency crises are usually associated with large nominal and real depreciations. In some countries depreciations are perceived to be very costly (“fear of floating”). In this paper we try to understand the reasons behind this fear. We first look at episodes of currency crises in the 1990s and establish that countries entering a crisis with high levels of foreign debt tend to experience large real exchange rate overshooting (devaluation in excess of the long-run equilibrium level) and large output contractions. We then develop a model of a small open economy that helps to explain this evidence. The key element of the model is the presence of a margin constraint on the domestic country. Real devaluations, by reducing the value of domestic assets relative to international liabilities, make countries with high foreign debt more likely to hit the constraint. When countries hit the constraint they are forced to sell domestic assets, and this causes a further devaluation of the currency (overshooting) and a reduction of their stock prices (overreaction). This fire sale can have a significant negative wealth effect. The model highlights a key tradeoff when considering fixed versus flexible exchange rate regimes; a fixed exchange regime can, by avoiding exchange rate overshooting, mitigate the negative wealth effect but at the cost of additional distortions and output drops in the short run. There are plausible parameter values under which fixed exchange rates dominate flexible exchange rates from a welfare perspective.