Impact of the Dollar Index on the Economy and Stock Market What Is the Dollar Index?The U.S. Dollar Index (DXY) measures the value of the U.S. dollar against a basket of six major world currencies, primarily the euro (EUR), Japanese yen (JPY), British pound (GBP), Canadian dollar (CAD), Swedish krona (SEK), and Swiss franc (CHF). A rising DXY indicates a strengthening dollar, while a falling DXY..