In finance, a foreign exchange swap, forex swap, or FX swap is a simultaneous purchase and sale of identical amounts of one currency for another with two different value dates (normally spot to forward). see Foreign exchange derivative. Foreign Exchange Swap allows sums of a certain currency to be used to fund charges designated in another currency without acquiring foreign exchange risk. It permits companies that have funds in different currencies to manage them efficiently. swap contract: swap contract is an agreement between two parties to exchange a cash flow in one currency against a cash flow in another currency according to predetermined terms and conditions.