Glossary / A-Book / B-Book

A-Book / B-Book

A-Book / B-Book are two models for how a broker or firm handles client trades: A-Book routes trades to the real market, while B-Book keeps them in-house, meaning the firm takes the other side of the trade. Most CFD prop firms operate funded accounts on a form of B-Book internally, regardless of what happens on the challenge phase.

This isn’t inherently a conflict of interest, it’s standard industry practice and part of how simulated funded accounts stay economically viable, but it’s the mechanism worth understanding before assuming a firm’s incentives are automatically aligned with a trader’s on every single trade.