USD - US Dollar
The USD – US dollar is the official currency of the United States of America. It is the world's leading currency represented by the currency code of USD or symbol $. The USD is widely used in most foreign transactions even passing as an official currency in countries outside of the U.S. including East Timor, Ecuador, El Salvador, the Marshall Islands, Micronesia, Palau among others. The currency was introduced through the Coinage Act of 1792 which laid emphasis on bimetallism, where the dollar equaled the value of determined amounts of gold and silver. It has reigned as the world's dominant reserve currency since the end of World War II. Around this time, the world's most developed countries signed the Bretton Woods Agreement where exchange rates of major currencies were pegged to the US dollar given the US was the world's most powerful economy.
In the foreign exchange market, the US dollar is a highly traded currency as more than 86% of forex trading involves the dollar. The currency pairs commonly known as the majors include USD pairs with EUR, JPY, GBP, CHF, AUD, CAD and NZD. There is always a demand for US dollars since the currency is necessary for use in international trade (gold and oil transactions are priced in USD). The Federal Reserve of the United States controls the monetary policy of the US.