If you're trading in the prop space and don’t know what “A-Book” or “B-Book” means — it’s time to catch up. These aren’t just broker terms. They define how risk is managed behind the scenes in prop firms, and most importantly, who profits when you win (or lose).
The A-Book model is the most transparent of all. When a trader is A-booked, their trades are passed directly to the market through a Liquidity Provider (LP) or broker. The prop firm is not taking the opposite side. If the trader wins, the market pays. If they lose, the market collects.
For the prop firm: Risk is capped to what’s funded as margin with the LP. Losses don’t come out of their own pocket.
For the trader: It’s real execution. No tricks, no games.
This model is gaining momentum. Firms like BullRush, FunderPro, and Alpha Capital are pushing A-Book funded accounts as part of their branding.
In the B-Book model, the firm keeps trades in-house. There is no external execution — the firm is literally taking the other side of your trade.
If you lose, the firm profits.
If you win, the firm pays from its own revenue — often funded by other traders’ challenge fees.
This is the dominant model in most retail prop firms. It’s easy to scale and doesn’t require putting capital with an LP. But it also creates a conflict of interest — especially when firms delay or refuse payouts.
The C-Book is where it gets murky. This is a hybrid model, where the firm monitors traders and decides:
In theory, it’s “smart risk management.” In reality, it’s often used secretly without informing traders — creating serious trust issues.
D-Book? Industry Slang Only
Some industry insiders joke about a “D-Book.” It’s not an official model — but a term used to describe:
It’s slang, but the idea reflects how some firms aggressively sort and control risk without transparency.
As more prop firms enter the scene, traders should know how their trades are handled. Ask questions. Look for transparency. And remember:
“A-Book firms manage risk. B-Book firms manage you.”
