A currency rate is the cost of one unit of a certain currency in relation to that of another currency. Currency rates are set by the central bank which exerts some form of control over the currency via the monetary policy it sets, taking into account established international common practice and legislative norms.
How and who sets the currency rates?
In Europe, for example, the rate for the euro against other currencies is set each day following a concertation procedure, whereby national banks which form part of the ECB, coupled with central banks from outside of Europe, set a rate for currencies against the euro.
How often are the ECB rates updated?
Rates are set following the concertation procedure at 15:15 EET each day and published on the ECB website shortly afterwards. As such the rates reflect the average market price at that time. Due to the rates being an average of the rate of buying and selling, they differ from the market rate. Private credit organisations and banks set their own rates by buying currency at less than the rate indicated by the ECB and selling it for more than the rate set by the ECB.