Currency collapses, defined as large nominal depreciations or devaluations, are associated with permanent output losses on the order of 6% of GDP on average. In this feature, we argue that the fact that these losses tend to materialise before a drop in the value of the currency indicates that it is not the large depreciation as such that is costly but the factors leading to the currency collapse. Taken on its own, the drop in the exchange rate actually has a positive effect on output.