The aim of this paper is to evaluate to what extent more transparency can reduce the occurrence of speculative attacks. It proposes a survey of the literature about the pros and cons of transparency on the exchange rate market, which is one of the main pillars of the new international financial architecture. The effects of transparency are shown to be ambiguous both from a theoretical and empirical point of views. However, the imperfect connection resulting from the confrontation between theory and empirics suggests that some new insights are necessary in order to better catch stylised facts on the one hand and to better evaluate the theory on the other, as has been done in recent literature. This leads to new proposals for economic and informational policies.