A-Book vs B-Book Explained for Forex Brokers One of the most important decisions every Forex broker must make is how client trades will be handled. Should trades be passed directly to external liquidity providers? Or should the broker internalize the risk and become the counterparty? This decision forms the foundation of the broker's execution model and is commonly known as A-Book and B-Book. While both models are widely used across the industry, each comes with its own adva