USD In currencies, this is the abbreviation for the U.S. dollar. Investopedia Says: The currency market, also known as the forex market, is the largest financial market in the world, with a daily average volume of over US$1 trillion. Related Terms: Base Currency Currency Currency Pair Exchange Rate Forex - FX Greenback Hard Currency Money Quote Currency USD In currencies, this is the abbreviation for the U.S. dollar. Investopedia Says: The currency market, also known as the forex market, is the largest financial market in the world, with a daily average volume of over US$1 trillion. Related Terms: Base Currency Currency Currency Pair Exchange Rate Forex - FX Greenback Hard Currency Money Quote Currency |