Forex Broker Conflicts of Interest: A-Book, B-Book and Dealing Desks

A forex broker has a conflict of interest whenever it takes the other side of your trade, because then your loss is its gain. Brokers that do this are said to keep trades on the B-book; brokers that pass trades to outside liquidity providers and earn a markup or commission are said to use the A-book, and most large retail brokers use some mix of the two.

In short: “A-book” and “B-book” are industry slang, not legal terms, but the underlying models are described plainly in public filings. A broker acting as counterparty earns spreads and, on top of that, any net losses its clients make on positions it has not hedged. That is not illegal, and regulated brokers disclose it. The problem comes when a broker claims it has no conflict when it does, which is what the CFTC found in its 2017 case against one of the largest US retail forex brokers.

The pitch you may have seen

Signal groups and broker affiliates often say things like “this broker is a true ECN, no dealing desk, so they want you to win”. Sometimes that is accurate. Sometimes it is a marketing label. Either way, the claim is about how your order is handled after you click “buy”, and it matters because many signal providers are paid by the same brokers they recommend (see how signal providers make money).

The mechanics

Model 1: the broker as counterparty (B-book, market maker, dealing desk)

The broker quotes a bid and an ask and fills your order itself. It now holds the opposite position. It can then:

net it against an opposite trade from another client, so that two clients’ positions cancel and the broker earns the spread from both;
hedge it in the wholesale market with a bank or other liquidity provider;
hold it, taking market risk on the net exposure that remains.

GAIN Capital, then a US-listed retail forex broker, described exactly this in its annual report for 2010 filed with the SEC. It said it “generally act[s] as the counterparty to our retail customers’ trades”, and that about 98% of its average daily retail volume was either “naturally hedged”, meaning one customer’s trade was offset by another’s, or hedged with a wholesale trading partner. On naturally hedged trades, it said, it had “the opportunity to capture the entire retail bid/offer spread on the two offsetting transactions”. It also acknowledged that “through our net exposure we are likely to have open positions” that could lose money.

Plus500, a CFD provider listed in London, reports a revenue line called Customer Trading Performance, defined in its annual reports as “gains/losses on customers’ trading positions”. Its reports state it expects this line to be broadly neutral over time, with most revenue coming from spreads and overnight charges.

Model 2: the broker as agent (A-book, STP, “no dealing desk”)

The broker passes your order to one or more outside market makers and earns a markup on the spread or a commission. FXCM’s annual reports filed with the SEC described its “agency model” this way: when a customer trades, it acts “as a credit intermediary, or riskless principal”, entering into offsetting trades with the customer and an outside FX market maker at the same time. In that model, the broker is paid by volume, not by your losses.

Even here there are smaller conflicts. An agency broker still earns more when you trade more, and it chooses which market makers to route to and on what terms.

Hybrid books

Most large retail brokers run both. A common approach described in the industry is to keep small, frequent, historically unprofitable accounts on the B-book, where the broker expects to keep their net losses, and route large or consistently profitable accounts to the A-book, where the broker hedges and earns only a markup. How brokers actually manage that risk is covered in how retail forex brokers hedge.

Worked example: what a B-book earns

Take a hypothetical broker with 1,000 retail clients over a year. Assume each client trades 50 standard lots, the broker earns 1 pip of spread ($10) per lot, and client results resemble the regulators’ loss figures: 80% lose an average of $1,500, 20% win an average of $1,200. (Illustrative figures.)

Revenue source	Calculation	Amount
Spread revenue	1,000 × 50 lots × $10	$500,000
Clients’ net trading result	(800 × −$1,500) + (200 × $1,200)	−$960,000
B-book gain if all trades kept unhedged	the opposite of the clients’ result	+$960,000
A-book alternative: 0.3-pip markup only	1,000 × 50 × $3	$150,000

On these assumptions, a fully B-booked broker earns more from clients’ net losses than from spreads. That is the core of the conflict. In practice brokers do not keep every trade unhedged, because a few large winning clients or a sudden market move can produce large losses on the net position, but the incentive points in one direction: the broker benefits when clients as a group lose. Real loss figures are in why most retail forex traders lose.

When the conflict became fraud: CFTC v. FXCM, 2017

On February 6, 2017, the CFTC ordered Forex Capital Markets LLC (FXCM), its parent and two founding partners to pay a $7 million civil penalty. According to the CFTC’s order:

From 2009 to at least 2014, FXCM told retail customers its “No Dealing Desk” platform had no conflicts of interest and that customers’ profits or losses would not affect its bottom line.
In fact, FXCM had an undisclosed interest in the market maker that won the largest share of trading volume on that platform and took positions opposite FXCM’s retail customers. The market maker had been spun off from FXCM, received a no-interest loan from FXCM, used FXCM’s offices and was staffed with FXCM employees.
The market maker rebated about 70% of its revenue from FXCM’s platform back to FXCM, about $77 million from 2010 through 2014.
FXCM made false statements to the NFA to conceal its role in creating the market maker.

FXCM and the two founders agreed to withdraw from CFTC registration and never to seek it again, and the NFA separately barred them from membership. FXCM left the US retail market. The lesson for traders is not that dealing desks are illegal; it is that “no dealing desk” is a claim, and claims need checking.

How regulators handle the conflict

United States. Only CFTC-registered retail foreign exchange dealers and futures commission merchants that are NFA members may act as counterparty to retail forex customers. When the CFTC adopted its 2010 rules, it cited the counterparty’s “inherent conflict” with its customers as the reason for requiring dealers to disclose, every quarter, the share of accounts that were profitable.
Canada. Forex dealers must be CIRO investment dealers, subject to its conflict-of-interest, best-execution and fair-pricing rules. See forex regulation in Canada.
EU and UK. Firms must identify and manage conflicts, act in the client’s best interest and meet best-execution rules. The 2018-2019 leverage limits and negative balance protection also limit how much a broker can earn from client losses.

Questions worth asking a broker

You do not need inside access to find out how a broker handles your trades. Most of it is in documents it has to publish:

In what capacity do you act on my trades? The customer agreement says whether the firm acts as principal (your counterparty) or as agent.
Do you internalise client orders, and how do you decide which accounts are hedged? A broker may not disclose its exact rules, but the order execution policy usually describes the approach.
Is slippage applied symmetrically? Ask whether price improvements are passed on as well as adverse moves.
Who regulates you, and where is my money held? Check the answer on NFA BASIC or CIRO’s dealer search rather than the broker’s website.
Do you pay anyone to refer me? If a signal provider sent you, it may be earning a rebate on every lot you trade.

What can go wrong

Marketing labels. “ECN”, “STP” and “no dealing desk” have no fixed legal definitions in retail forex. The customer agreement and order execution policy are where a broker says whether it acts as principal.
Price manipulation by a dealer. A counterparty broker controls the prices you trade at. In 2011 the NFA fined FXCM $2 million and the CFTC ordered a further $6 million penalty plus restitution for asymmetric slippage: passing on price moves that went against customers while keeping moves in their favour. NFA rules now say any such asymmetric settings violate its standards.
Offshore firms. A B-book broker with no regulator has no disclosure duty, no capital requirement and no one to answer to if it refuses withdrawals.
Affiliate signals. A signal provider paid per lot by a counterparty broker is paid more when you trade more, and the broker on the other side may profit when you lose. Both incentives point the same way.

The takeaway

A broker that takes the other side of your trades is not automatically dishonest, and many regulated brokers do it openly. But it means the firm’s revenue rises when clients lose, and the 2017 FXCM case shows what happens when that is hidden behind a “no conflict” label. Read the customer agreement’s description of how orders are executed, check registration on NFA BASIC or CIRO’s dealer search, and treat any “this broker wants you to win” pitch as marketing.