The Dow Jones FXCM Dollar Index (USDOLLAR) is an index (or measure) of the value of the United States dollar relative to a basket of four currencies: the Euro, the British Pound, the Japanese Yen, and the Australian Dollar.
The index rises when the US dollar gains value against the other four currencies.
The Index falls when the US Dollar loses value against the other currencies.
As of January 1, 2011, the Dow Jones FXCM Dollar Index was a measure of the U.S. dollar's value equally weighted against four of the world's most liquidly traded currencies: The equation[2] As time goes by, currency weightings will deviate from their original 25% as currency prices fluctuate.
[2] The Dow Jones FXCM Dollar Index (USDOLLAR) is a collaboration between Dow Jones Indexes and FXCM.