ModelBeginner
B-Book
An execution model where the broker acts as counterparty to the client, internalizing the order rather than routing it to an external liquidity provider.
Last updated: February 1, 2026
1
Client places a trade order.
2
Instead of routing the order externally, the broker internalizes it — acting as the counterparty.
3
The broker takes the opposite side of the client's position.
4
If the client loses, the broker profits; if the client wins, the broker loses.
5
Some B-book brokers hedge net exposure periodically, but the default is internalization.