Currency rates vary from day to day and, every day in which there is currency trading, the value of a particular currency will change compared with other days.
There are a number of factors that have an effect on currency rates and the major factors include the amount of money that a particular country prints, government and central bank intervention in establishing the currency value and changes in the value of foreign currency rates.
Currency exchange or cross rates are the rates of two types of currencies based on the value of a third currency type. In Israel, the currency rates are usually computed by comparing them with the US dollar.
Calculating and quoting currency rates without using the value of the US dollar is called a cross rate; for example, computing the value of the euro using the values of the Japanese yen and British pound sterling.