A floating exchange rate or fluctuating exchange rate is a type of exchange rate regime wherein a currency's value is allowed to fluctuate according to the foreign exchange market.Management by the central bank may take the form of buying or selling large lots in order to provide price support or resistance, or, in the case of some national currencies, there may be legal penalties for trading outside these bounds.A currency that uses a floating exchange rate is known as a floating currency.The debate of making a choice between fixed and floating exchange rate regimes is set forth by the Mundell,Fleming model, which argues that an economy cannot simultaneously maintain a fixed exchange rate, free capital movement, and an independent monetary policy. There are economists who think that, in most circumstances, floating exchange rates are preferable to fixed exchange rates. As floating exchange rates automatically adjust, they enable a country to dampen the impact of shocks and foreign business cycles, and to preempt the possibility of having a balance of payments crisis.In certain "high" relative to others, such as the UK or the Southeast Asia countries before the Asian currency crisis. It can choose any two for control, and leave the third to market forces.In cases of extreme appreciation or depreciation, a central bank will normally intervene to stabilize the currency. Thus, the exchange rate regimes of floating currencies may more technically be known as a managed float. A central bank might, for instance, allow a currency price to float freely between an upper and lower bound.