An exchange rate (also known as a foreign-exchange rate) between two currencies is the rate at which one currency will be exchanged for another. It is also regarded as the value of one country's currency in terms of another currency.
Exchange rates are determined in the foreign exchange market, which is open to a wide range of different types of buyers and sellers and where currency trading is continuous: 24 hours a day except weekends (from 20:15 GMT on Sunday until 22:00 GMT on Friday). The spot exchange rate refers to the current exchange rate. The forward exchange rate refers to an exchange rate that is quoted and traded today, but for delivery and payment on a specific future date.
Since the beginning of 2018, the dollar has shed 3.0% of its value against the Japanese yen as concerns about global growth have ratcheted up demand for safe haven assets and expectations of a slower pace of interest rate increases at the Federal Reserve sapped demand for the dollar.
The dollar versus the European exchanges: for GBP/USD the pound sterling is up roughly 2.1% YTD. The EUR/USD is currently about 0.8% higher for 2018.
The ICE U.S. Dollar index, a gauge of the dollar's value against a basket of six currencies, has dropped steadily since the beginning of 2018 ( 0.5%) and as of May 1 stands at 91.83.
The U.S. Dollar Index is a weighted geometric mean of the dollar's value relative to the following select currencies and their corresponding weight: EUR (57.6%), JPY (13.6%), GBP (11.9%), CAD (9.1%), SEK (4.2%) and the Swiss Franc, CHF (3.6%).