A broker model where client trades are kept in-house (not routed to the market) — the broker takes the other side and profits from losses.
B-book is a broker's internal order handling model where client trades are kept on the broker's books rather than being routed to external liquidity providers. The broker takes the opposite side of every B-book trade — if the client loses, the broker wins, and vice versa. B-book is the default model for market maker brokers.
Brokers use B-book because it's profitable. Most retail forex traders lose money over time, so holding the other side of their trades is a positive expectation business for the broker. Large, profitable clients get moved to A-book (where their trades are routed to LPs) to protect the broker from big losers. Losing clients stay in B-book.
B-book isn't automatically unethical, but it creates a conflict of interest. The broker profits when you lose, which incentivizes bad behavior like slippage, re-quotes, and "platform issues" during volatile moves. Regulated brokers are less likely to engage in this, but the structural incentive still exists.
Forex.com and FXCM have both been fined by US regulators for B-book practices that disadvantaged profitable clients. The fines ran into tens of millions of dollars and served as warning shots to the industry.
Frequently asked about b-book
What is a b-book in trading?+
A broker model where client trades are kept in-house (not routed to the market) — the broker takes the other side and profits from losses.
When will I see b-book used in real trading?+
At almost every market maker broker. B-book is standard operating procedure for retail forex market makers.
What is the most common mistake traders make with b-book?+
Assuming the broker hedges every B-book trade externally. They don't — the whole point of B-book is to internalize the exposure and keep the spread plus any losses.
What do experienced traders know about b-book that beginners don't?+
If you're consistently profitable, your broker may automatically move you from B-book to A-book. If you suddenly experience worse execution after a winning streak, you might be a victim of this shift. Consider moving to a genuine ECN broker to eliminate the issue.
Read the lesson here. Mark the chart on TradingView. Compare brokers with the checklist.
TradingView is the chart workspace most learners already recognize: watchlists, alerts, drawings, and clean multi-market charts. Broker research stays methodology-first: jurisdiction, costs, platform, withdrawals, and risk before any account decision.