The subject of this thesis is to evaluate the main causes of instability in the foreign exchange market in selected countries. The first part is devoted to a summary of the basic theoretical knowledge about the foreign exchange market, its organization and operations of entities intended to hedge against exchange rate risk. The second part focuses on the exchange rate systems. The third chapter focuses on chosen economies, which are included in the final analysis. The main point of the analytical part is focused on the development of turnover on the foreign exchange market in selected countries in terms of the nature of the operations, currency and traded entities. The comparison of the dynamics and structure of the foreign exchange market turnover in selected countries, the system takes into account the applicable exchange rate. Sweden, Denmark, Hungary and Bulgaria were chosen for the analysis, performed during the period 2002 - 2011