Forex is different from from equities or futures trading because your broker can choose to all your trade against you. This is known as B booking. When your broker sends all your trades to the real market or their liquidity providers, this is known as A Booking.

In Forex, your broker can keep your trades ' in house' This means that your trades are not sent to the real market.

Instead, your broker bets against you, taking the other side of the trade. For example, if you were to buy 1 lot of EURUSD at 1.35000, then your broker would be selling 1 lot of EURUSD 1.35000. If you win, your broker loses, vice versa.

In the forex market, the A Book and the B Book refer to two separate ways brokers handle customer trades. With the A Book model, brokers pass traders’ orders directly to external liquidity providers or the broader financial market. The broker mainly earns through commissions or spreads and is not affected by the trader’s profit or loss. This setup is often viewed as more transparent because there is less conflict between the broker and the client.

The B Book model works differently. Instead of forwarding trades to outside markets, the broker manages them internally and may take the opposite side of the trader’s position. In this case, the broker can benefit when traders lose money, but may lose when traders make profits. Due to this structure, some traders are cautious about possible conflicts of interest. Today, many forex brokers use a mixed approach, combining A Book and B Book systems to balance risk management and improve operational efficiency.