Investors who trade stocks, futures, or options typically use a broker who acts as an agent in the transaction. The broker takes the order to an exchange and attempts to execute it per the customer’s instructions. The broker is paid a commission when the customer buys and sells the tradable instrument for providing this service.
The FX market does not have commissions. Unlike exchange-based markets, FX is a principals-only market. FX firms are dealers, not brokers. Unlike brokers, dealers assume market risk by serving as a counterparty to the investor’s trade. They do not charge commission; instead, they make their money through the bid-ask spread.
In FX, the investor cannot attempt to buy on the bid or sell at the offer as is the case in exchange-based markets. On the other hand, once the price clears the cost of the spread, there are no additional fees or commissions. Every single penny gained is pure profit to the investor. Nevertheless, the fact that traders must always overcome the bid/ask spread makes scalping much more difficult in FX.