A-Book vs B-Book Brokers: Differences, Conflicts of Interest and How to Check

An A-book broker passes your order on to a liquidity provider or the market, so it does not take the opposite side of your trade. A B-book broker keeps the other side itself, which means it is your counterparty. The two models are not good and bad: both are legal when disclosed, and many brokers run a hybrid. What matters to you is the conflict of interest in B-book execution and the fact that you cannot reliably tell from the outside which model a broker uses.

Disclosure: OnForex may earn a referral commission from Exness links on this page. This is general education, not investment advice.

This guide explains how each model works, why the label "A-book" proves less than it sounds, how to check a broker as well as anyone can, and what Exness itself says in its Help Center (checked 2 November 2026).

A-book vs B-book: how each model works

	A-book (agency / pass-through)	B-book (market maker / dealing desk)
Who takes the other side	A liquidity provider or the market	The broker
How the broker earns	Spread markup and/or commission	Spread, commission, swaps, and also the net result of client trades if it keeps the risk
When a client loses	The broker is paid its fee either way	The broker may gain what the client loses
Typical labels	STP, ECN, "no dealing desk"	Market maker, dealing desk
Main risk for the client	Rejections or slippage in fast markets	Conflict of interest over price and execution

A worked example. You buy 1 lot of EUR/USD and close with a loss of 100 USD. In an A-book flow, the broker's own result does not depend on that loss, because the order was passed on. In a B-book flow, if the broker kept the position unhedged, that 100 USD is, before costs, the broker's gain. That is the conflict of interest: the broker is paid by the same price feed and execution that decides whether you win or lose.

This does not mean a B-book broker acts against you. Many market makers run large books where buy and sell orders partly offset (netting) and hedge only the net exposure. It does mean that the incentive exists, so rules and disclosure matter.

Hybrid models: most brokers are neither

In practice the split is usually not 100/0. A hybrid broker routes some flow outward and keeps the rest. Industry descriptions of hybrid routing mention criteria such as account size, trade size, strategy and recent profitability. Those criteria are internal and are not something clients can see, which is why a broker saying "we are A-book" or "we are B-book" tells you only part of the story.

How STP, ECN and "market maker" fit in

These words describe different things and are often mixed up:

• Market maker / dealing desk: the broker quotes its own prices and is the counterparty.
• STP (straight-through processing): orders are sent on automatically without manual intervention. The destination can be a liquidity provider or the broker's own system, so STP alone does not prove A-book.
• ECN: a network where orders from many participants match against each other. A true ECN connection is uncommon for retail accounts, and "ECN-style" often just means raw spread plus commission.

Always ask what the broker means by the label and where the contract says it.

Can you tell if a broker is A-book? What you can and cannot check

Honestly, not from your own trades. Here are the usual signals and why none is conclusive:

Signal	Why people use it	Why it is weak
Very tight spread	Looks like raw market pricing	Both models can show tight spreads on majors
Slippage both ways	Real market access has positive and negative slippage	Either model can produce this; one-sided slippage is a warning but not proof
Different prices from another broker	Suggests an independent feed	Feeds differ for many harmless reasons
Orders rejected only on winners	Suggests risk management against profitable clients	Rejections also happen in fast markets
"ECN" or "STP" in marketing	Claimed execution type	Marketing; the contract decides

The stronger evidence is written:

1. Order execution policy. Many regulators require firms to have an order execution policy, and brokers usually publish it. Look for wording on whether the firm is the counterparty and trades on its own account.
2. Client agreement. Check the clauses on execution venue, dealing on own account and conflicts of interest.
3. Regulator and complaints record. Check the regulator's register for the entity you actually contract with.
4. Withdrawal test. Withdraw a small profit early. Disputes over profitable accounts are where the conflict of interest shows up most.

A simple test you can run yourself: log 20 to 30 market orders on a demo or small live account, with the requested price, filled price and market conditions. Count the share of fills that were better, equal or worse than requested. A strong tilt to worse fills in calm markets is worth investigating; a mixed result means the sample cannot separate the models.

What Exness says officially

The Exness Help Center article "Execution" (updated 4 September 2026, checked 2 November 2026) says that:

• the applicable Exness entity is your sole counterparty, so you trade with it directly and not with the underlying market or exchange;
• the entity, or another Exness entity, acts as the market maker, with liquidity and execution provided internally;
• its quotes are built from raw data from multiple independent sources and processed with proprietary models;
• its revenue comes from spreads, commissions and swaps, and not from the outcome of individual client trades, and natural netting can occur across buy and sell orders;
• it avoids labelling its services with market titles such as A-book or B-book and describes how the model works instead.

The article does not say how, or whether, Exness hedges its net exposure, so this page does not claim either. In its answer on account types (updated 29 September 2026) the Help Center also states that Exness does not provide ECN accounts. Two execution types exist: market execution, and instant execution on Pro accounts only (Help Center article on order and execution types, updated 19 September 2026). Execution speed and price are not guaranteed: delays and slippage can occur, especially around news and market open. Which entity serves you depends on your country and is shown in your Personal Area. See Exness account types for how the account types differ.

Sources: Exness Help Center, Execution, What trading account type should I use? and Available order and execution types, all checked 2 November 2026.

How to choose with the conflict of interest in mind

1. Pick a regulated entity and read its order execution policy. Regulation does not remove the conflict, but it adds disclosure duties and complaint routes.
2. Know the real costs. Compare spread, commission and swap on the instruments you trade. See spread explained and swap explained.
3. Measure execution yourself. Slippage and requotes are measurable. See slippage in forex.
4. Avoid strategies that depend on a tiny edge. Scalping with a 0.5 pip target is most sensitive to execution quality, so test it on a demo account first.
5. Do not rely on the label. Whether a broker calls itself A-book, B-book, STP or ECN, trade only size you can afford to lose.

Frequently asked questions

What is the difference between an A-book and a B-book broker?

An A-book broker passes your order on; a B-book broker keeps the other side. The result is a different incentive structure, not a guarantee of better or worse prices.

Is a B-book broker a scam?

No. Market-making is a legal business model at many regulated firms. Judge a broker by regulation, written disclosure and payout behaviour, not by the label.

How can I tell if my broker is A-book?

You cannot reliably tell from your own fills. Read the order execution policy and the client agreement, and test small withdrawals.

Is Exness A-book or B-book?

Exness avoids both labels. Its Help Center describes the Exness entity as your counterparty and market maker, with revenue from spreads, commissions and swaps.

Does Exness offer ECN accounts?

The Help Center says no. Raw Spread and Zero accounts are low-spread accounts with a commission.

Further reading

• Spread explained
• Slippage in forex
• Forex order types
• How to choose a forex broker
• Exness account types

Risk warning: Forex and CFD trading carries a high risk of loss, and you can lose more than you deposit with some products. CFDs are complex instruments and are not suitable for everyone. Past performance does not guarantee future results. Whether a broker is A-book, B-book or hybrid does not change this risk. Nothing here is a recommendation to trade.