Currency prices are constantly moving, so the trader may decide to hold the position overnight. The broker will rollover the position, resulting in a credit or debit based on the interest rate differential between the Eurozone and the U.S. If the Eurozone has an interest rate of 4% and the U.S. has an interest rate of 3%, the trader owns the higher interest rate currency because they bought EUR. Therefore, at rollover, the trader should receive a small credit. If the EUR interest rate was lower than the USD rate then the trader would be debited at rollover.

In this view, countries may develop unsustainable economic bubbles or otherwise mishandle their national economies, and foreign exchange speculators made the inevitable collapse happen sooner. A relatively quick collapse might even be preferable to continued economic mishandling, followed by an eventual, larger, collapse. Mahathir Mohamad and other critics of speculation are viewed as trying to deflect the blame from themselves for having caused the unsustainable economic conditions.
Unlike stock markets, which can trace their roots back centuries, the forex market as we understand it today is a truly new market. Of course, in its most basic sense—that of people converting one currency to another for financial advantage—forex has been around since nations began minting currencies. But the modern forex markets are a modern invention. After the accord at Bretton Woods in 1971, more major currencies were allowed to float freely against one another. The values of individual currencies vary, which has given rise to the need for foreign exchange services and trading.