A-Book vs B-Book: How Your Broker Really Handles Your Trades

By The Elephant in the Room. Eight years on the inside of forex brokers, now explaining the parts the marketing department left out.

If you only learn one piece of jargon before you fund a trading account, make it this one. The whole question of a-book vs b-book comes down to a single thing your broker decides the instant you hit “buy”: do they send your trade to the real market, or do they keep it for themselves and bet against you?

That decision quietly determines whether your broker is rooting for you or rooting against you. Most traders never find out which side they’re on, and the brokers like it that way. So let’s pull it apart in plain English.

(If you haven’t read it yet, this builds on the bigger picture in how forex brokers make money, so start there if you want the full map.)

A-book: your broker is a messenger

An A-book broker passes your order straight through to the real market, to liquidity providers like banks, prime brokers, or an ECN that actually fills it. You’ll see this model branded as STP (straight-through processing), ECN, DMA, or “agency execution.”

The broker never takes a position against you. They’re a messenger with a meter running. They make their money two ways: a small markup added to the spread, or a fixed commission per lot you trade. That’s it.

Here’s why this matters to you. An A-book broker’s incentive is volume and longevity. They want you trading often and surviving long enough to keep trading. Whether you win or lose on any given trade is genuinely none of their business, because they’ve already been paid. There’s no conflict of interest baked into the relationship.

B-book: your broker is the casino

A B-book broker does the opposite. They don’t send your trade anywhere. They take the other side of it themselves, so they are the counterparty. You’ll hear this called a “dealing desk,” “market maker,” or “principal” model.

Now the maths gets uncomfortable. When you lose, the broker keeps your money directly. When you win, they pay you out of their own pocket. So their profit and your profit are in direct opposition.

Why would any broker want that risk? Because of the number they’re legally required to print on their own adverts: in regulated markets, somewhere around 70% to 85% of retail accounts lose money. If you know the house statistically wins, taking the other side of retail trades isn’t reckless. It’s the most profitable seat at the table. The losses aren’t an accident the broker tolerates. On a B-book, they’re the product.

The bit nobody explains: most brokers do both

Here’s where the textbook version falls apart. Serious brokers don’t pick a side. They run a risk book and sort clients in real time. This is the part I watched up close, and it’s more clinical than you’d think.

First, they net you off against each other. If one client is long EUR/USD and another is short the same size, those cancel out inside the broker’s books, leaving no risk and pure spread profit. They only need to hedge the leftover net exposure with a real liquidity provider.

Then they segment by who you are as a trader:

Losing and inexperienced traders get B-booked. The broker keeps the trade because they expect to keep the money. This is most retail clients.
Consistently profitable or “sharp” traders get A-booked (quietly routed out to the market) so the broker isn’t the one paying when you win. Scalpers, news traders, and anyone who looks like a professional often get flagged and routed out fast.

A risk engine scores you on your behaviour and makes this call automatically, often within milliseconds. The dark irony: the better you get, the more likely your broker stops betting against you and starts just charging you a toll. Most traders never trade well enough to get “promoted” out of the B-book.

So is B-book just a scam?

No, and this is where the honest version matters, because the internet is full of people who’ll tell you any market maker is robbing you. That’s lazy.

B-book execution is legal, extremely common, and run by some of the most reputable, heavily-regulated brokers in the world. For a small retail trader it can even be better: instant fills, no requotes, and the ability to trade tiny position sizes that no bank would bother quoting. The broker’s edge is statistical, not necessarily rigged. They expect to win over thousands of clients the way a casino expects to win over thousands of hands, without needing to cheat any single one.

The danger isn’t the B-book itself. It’s the conflict of interest it creates, and the minority of operators who exploit it: asymmetric slippage that only ever goes against you, suspicious spikes that hunt your stop-losses, platforms that “lag” at the worst moment, and withdrawal processes that suddenly need three more documents once you’re up. A regulated B-book broker has a reputation and a license to protect. An offshore one with a flag-of-convenience license has neither.

How to tell which one has you

Brokers rarely volunteer this, but the tells are there if you look:

Read the order execution policy. Buried in the legal docs, brokers often state whether they “may act as principal” (B-book) or route to third parties (A-book). The phrase “we may be the counterparty to your trades” is a B-book confession in a suit.
Look at the account types. Commission-free “Standard” accounts with wider spreads are usually B-booked. “Raw,” “ECN,” or “Pro” accounts that charge a commission for tighter spreads are more likely routed to market. Not a guarantee, but a strong hint.
Check the regulator and the entity. Which legal entity is your account actually under? A trade with the UK or Australian entity of a broker is a very different animal from the same brand’s offshore entity in a jurisdiction with no real oversight. The offshore entity is where the aggressive B-booking lives.
Just ask. Email support: “Do you operate a dealing desk? Are you the counterparty to my trades?” How clearly (or evasively) they answer tells you most of what you need to know.

What this actually means for you

If you’re a casual trader putting small money to work, a well-regulated B-book broker is a perfectly reasonable choice: you’ll get clean fills and you’re protected by the regulator, conflict of interest or not. If you’re serious about scaling, becoming consistently profitable, or running strategies like scalping or news trading, you want genuine A-book/ECN execution, because the last thing you want is a counterparty who loses money every time you win, and who has a hundred quiet levers to make sure that doesn’t happen often.

Either way, the goal is the same as everything else on this site: trade knowing who’s on the other side of the table. The elephant in the room with your broker is that, a lot of the time, the other side of the table is your broker.

Frequently asked questions

What does a-book vs b-book mean in forex? A-book means your broker passes your trades to the real market and earns a markup or commission, so they don’t profit from your losses. B-book means your broker is the counterparty to your trades and keeps your losses as revenue. Many brokers run both and route clients based on profitability.

Is a b-book broker bad? Not inherently. B-book (market-maker) execution is legal, common, and used by major regulated brokers, and it can mean faster fills and smaller trade sizes for retail clients. The risk is the conflict of interest and a minority of operators who exploit it through slippage, stop-hunting, or withdrawal friction.

How do I know if my broker is a-book or b-book? Check the order execution policy in their legal documents, look at whether your account type is commission-free (often B-book) or commission-based ECN/Raw (often A-book), confirm which regulated entity holds your account, and ask support directly whether they operate a dealing desk.

Which is better, a-book or b-book? For small, casual traders, a regulated B-book broker is usually fine. For traders aiming to be consistently profitable or running scalping and news strategies, true A-book/ECN execution is safer because the broker has no incentive to work against your wins.