In order to trade on a margin, you must set up a margin account. With a relatively small deposit you can start trading large amounts of currency. Establishing a margin account with a FOREX broker enables you to borrow money from the broker to control currency lots that are usually worth $100,000. The amount of borrowing power your margin account gives you is the leverage. 100 - 1 means that with a single dollar you can control $100 worth of currency.