B-Book
A model where the firm takes the other side of your trade internally rather than routing it to market — common in simulated environments, and a reason to judge firms by their payout record.
B-booking means the firm holds your trade internally instead of passing it to the market. Your profit is paid from the firm’s own funds; your loss stays with the firm. It’s the counterpart to the A-book model, where orders go out to real liquidity and the firm earns from fees.
This is worth understanding without any drama attached. Nearly every prop firm runs evaluations in a simulated environment — that’s the sensible design, since the firm is assessing your skill before it puts capital behind you. Some firms continue to run funded accounts in simulation too, managing aggregate risk internally and paying withdrawals out of firm revenue. Others route funded traders to live markets. Both structures exist, and both have paid traders well.
What it means for you in practice: the structure a firm uses matters less than whether it pays, consistently, at scale, over time. That’s a fact you can check — and it’s the fact worth checking.
The signals that separate the firms worth your evaluation fee:
- A long, public payout history, ideally with verifiable proof from many different traders.
- Rules applied consistently, without terms that shift after a big win.
- Sensible risk rules — drawdowns and contract caps that a competent trader can work within.
- Straight answers about how funded accounts are executed, when you ask support directly.
Where the model does deserve a sharper eye is in less transparent corners of the CFD and forex space, where the firm sets the price as well as taking the other side. Ask more questions there.
The good news for US traders: the futures side is built on exchange-priced products, and the strongest firms compete openly on payout speed and reliability, which is exactly the competition you want them having.
Judge the payout record above all. Read prop firm red flags and how prop firms make money, then compare firms in our directory.