Dealing Desk vs No Dealing Desk (ECN/STP): Broker Execution Models Explained

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Why the Execution Model Matters

When you click buy or sell, your order does not float into an abstract “market.” It goes to a specific place, chosen by your broker's execution model. That model determines who takes the other side of the trade, how your spread and commission are priced, and whether your broker makes money from your activity or from your losses. Two brokers can quote the same pair and feel completely different once you understand what happens after you click.

The industry splits execution into two broad camps: dealing desk (market making) and no dealing desk (NDD). Inside NDD sit the STP, ECN and DMA variants. The labels get used loosely in marketing, so this guide sticks to what each one actually does, what it costs you, and how to verify which one you are really dealing with — rather than moralising about market makers the way many comparison sites do.

The Four Models at a Glance

Model	Where your order goes	Typical pricing	Conflict of interest
Market Maker (Dealing Desk / B-book)	Internalised — the broker is your counterparty	Fixed or fixed-ish spreads, usually no separate commission	Direct — the broker profits when you lose, unless it hedges
STP (No Dealing Desk)	Passed straight through to one or more liquidity providers	Variable spread marked up over the LP price, usually no commission	Reduced — the broker earns from the markup, not your loss
ECN (No Dealing Desk)	Matched in an aggregated order book of banks, funds and other traders	Raw / near-zero spread plus a fixed commission per lot	Lowest — the broker is paid per volume, indifferent to your P&L
DMA (Direct Market Access)	Sent directly to the underlying venue or LP order book	Exchange / LP price plus commission	Lowest — pure agency execution

Dealing Desk / Market Maker (B-book)

A dealing desk broker is a market maker. It creates a market for you in-house: it quotes both a bid and an ask, and when you take a position it takes the opposite one. You are trading against the broker, not against the wider market. This is the oldest retail model and it is how a large share of fixed-spread, commission-free accounts still work.

The advantages are real. A market maker can offer tight, stable fixed spreads, fill your order instantly even when the underlying market is thin, and support very small trade sizes that a bank liquidity provider would not bother quoting. For beginners and modest accounts, that predictability is genuinely useful.

The catch is the conflict of interest. Because the broker is your counterparty, its trading book profits when your positions lose. In the hands of an unregulated offshore firm that historically meant requotes, asymmetric slippage, and platform “glitches” at inconvenient moments. A well-run, EU-regulated market maker manages the same conflict very differently — it hedges net exposure with liquidity providers and is bound by MiFID II best-execution rules — but the structural incentive is still worth understanding before you open the account.

No Dealing Desk: STP, ECN and DMA

A no dealing desk broker does not sit on the other side of your trade. Instead it routes your order out to third-party liquidity — banks, non-bank market makers, funds and other traders — and earns from a markup or a commission rather than from your loss. There are three common variants.

STP (Straight-Through Processing) passes your order directly to one or more liquidity providers. The broker takes the best available LP price and adds a small markup to the spread, so STP accounts usually show variable spreads and no separate commission. It is the simplest NDD model and a common default for standard accounts.

ECN (Electronic Communication Network) plugs you into an aggregated order book where many participants post prices. You see the rawest spread available — often fractions of a pip on majors — and pay a transparent fixed commission per lot instead of a markup. ECN accounts typically expose a depth-of-market ladder so you can see resting liquidity. This is the model most used by scalpers and high-volume traders.

DMA (Direct Market Access) takes it a step further, sending your order straight to the underlying venue or LP order book with no dealer intervention at all. It is pure agency execution, priced with a commission, and is more common in equities and among professional-tier clients than in mainstream retail forex.

A-book vs B-book — and Why Most Brokers Run a Hybrid

Underneath the marketing labels, every broker makes one decision per trade: hedge it or keep it. Hedging it — offsetting your position with a liquidity provider so the broker carries no directional risk — is called A-booking. Keeping it in-house, unhedged, so your loss becomes the broker's profit, is called B-booking.

Here is the part competitors rarely state plainly: almost every regulated broker runs both at once. This is a hybrid model. The broker's risk engine watches client behaviour and routes flow accordingly — consistently profitable clients and large orders tend to be A-booked (hedged, because the broker does not want to be on the losing side of a skilled trader), while the aggregate of small retail flow, which statistically nets to a loss, is warehoused B-book. Internalising that flow is cheaper than paying to hedge every ticket, and it is legal, disclosed in the execution policy, and used by household-name EU brokers.

So “is my broker A-book or B-book?” is usually the wrong question. The realistic answer is “both, depending on the trade.” What actually protects you is not the routing label but the regulator behind it: an EU licence brings negative-balance protection, segregated client money, and a best-execution duty that a hybrid book has to respect regardless of which way it routes a given order.

How to Tell Which Model Your Broker Uses

You cannot see the internal routing, but the account structure leaves fingerprints. These signals are indicative, not definitive — read them together rather than in isolation.

What you observe	What it suggests
Raw spread near 0.0 pips with a separate per-lot commission	ECN, A-book leaning
Fixed spreads and no commission	Market maker (B-book)
“Market execution” order type with slippage in both directions	No dealing desk (STP or ECN)
“Instant execution” with requotes on fast-moving markets	Dealing desk
A depth-of-market (Level 2) ladder inside the platform	ECN
A published order-execution and best-execution policy	Any MiFID II firm — every EU-regulated broker

The most reliable public document is the broker's order-execution policy, which every MiFID II firm must publish. It names the execution venues and describes how orders are handled. It will not confess the A-book/B-book split on your individual trades, but it tells you whether the firm is a serious, EU-supervised operation or an offshore shell with a one-line disclaimer.

Which Model Suits Scalpers, News Traders and Long-Term Traders

Scalpers and high-frequency traders should favour ECN. Raw spreads keep the per-trade cost low, and genuine no-dealing-desk routing avoids the requotes and short-term-trade restrictions some market makers impose. The commission is worth it once your trade count is high.

News traders care most about execution during volatility. NDD/ECN routing with transparent market execution and symmetric slippage is preferable to a dealing desk that may requote or widen aggressively around releases. Our execution-speed test measures exactly how brokers behave when markets move.

Long-term and position traders place few trades and feel spread cost far less, so the simplicity of a commission-free, fixed-spread market-maker account is a reasonable choice — provided the broker is EU-regulated. For this profile, custody, regulation and platform stability matter more than shaving a fraction of a pip.

What ESMA and MiFID II Do — and Don't — Police About Execution

EU rules regulate execution more tightly than most traders realise, but not in the way the A-book/B-book debate implies. Under MiFID II, every investment firm owes a best-execution duty: it must take all sufficient steps to obtain the best possible result for the client across price, cost, speed, likelihood of execution and settlement. It must maintain and publish an order-execution policy, and firms have historically had to disclose their top execution venues in periodic reporting.

ESMA's product-intervention measures add the protections that matter to retail clients regardless of execution model: leverage caps, negative-balance protection, standardised risk warnings, and the ban on binary options. A market maker and an ECN broker serving the same EU client are bound by exactly the same rules here.

What the rules do not require is per-trade routing disclosure. No regulation forces a broker to tell you whether a specific order was internalised (B-book) or hedged (A-book). The framework polices the outcome — did you get a fair price consistent with the execution policy — not the internal risk decision on each ticket. That is why comparing measured, all-in trading cost matters more than chasing a routing label, which is precisely what our EU Broker Execution Index and spread-index data are built to do.

Frequently Asked Questions

What is the difference between a dealing desk and a no dealing desk broker?

A dealing desk broker (a market maker) takes the opposite side of your trade in-house — when you buy, it sells to you, so it is your direct counterparty. A no dealing desk (NDD) broker passes your order out to external liquidity providers, either straight through (STP) or into an aggregated order book (ECN). With a dealing desk, the broker sets the price and can profit from your loss; with NDD, the broker earns from a spread markup or a commission and is more indifferent to whether you win or lose.

Is a market maker broker bad?

No — market making is a legitimate, regulated business model, not a scam. Market makers provide guaranteed liquidity, tight fixed spreads, and instant fills even in thin markets, which suits beginners and smaller accounts. The issue is the conflict of interest: because the broker is your counterparty, its book profits when clients lose. A well-run market maker manages that with risk controls and by hedging exposure; the reputation problem comes from a minority of offshore firms that abused it with requotes and asymmetric slippage. Inside the EU, best-execution rules and CySEC/BaFin/AMF supervision constrain that behaviour.

What does A-book vs B-book mean?

A-book means the broker offsets your trade with a liquidity provider, so your position is hedged in the real market and the broker earns from the spread markup or commission. B-book means the broker keeps your trade on its own book (internalises it) and does not hedge, so your loss is the broker's gain and vice versa. Most regulated brokers run a hybrid: consistently profitable or large clients are routed A-book, while the aggregate of smaller retail flow — which statistically nets to a loss — is warehoused B-book. This is standard risk management, disclosed in the execution policy, not evidence of foul play.

How can I tell if my broker is a market maker?

Look at the account pricing. Fixed spreads with no commission almost always mean market making. Raw or near-zero variable spreads plus a per-lot commission, a depth-of-market ladder, and “market execution” order types point to an ECN or STP no-dealing-desk model. Requotes on fast markets suggest a dealing desk. You can also read the broker's order-execution policy, which every MiFID II firm must publish — it names the execution venues and describes how orders are handled, though it will not tell you whether an individual trade was A-booked or B-booked.

Are ECN brokers always cheaper?

Not automatically. ECN accounts show a raw spread but add a commission, typically around 6 USD per standard lot round-turn. For an active trader the all-in cost (raw spread plus commission) is usually lower than a market maker's marked-up fixed spread, especially on major pairs. For someone who trades rarely or in small size, a commission-free fixed-spread account can work out simpler and no more expensive. The honest comparison is always spread plus commission together, which is exactly what our EU Broker Execution Index and spread-index data measure.

Does ESMA or MiFID II require a broker to tell me if it B-books my trades?

No. MiFID II imposes a best-execution obligation — the broker must take all sufficient steps to obtain the best possible result for you across price, cost, speed and likelihood of execution — and it must publish an order-execution policy and, historically, venue-level reporting. But none of that forces a broker to disclose, trade by trade, whether it internalised your order (B-book) or hedged it (A-book). Regulation polices the outcome and the policy, not the internal routing decision on each ticket.

Which execution model is best for scalping?

Scalpers and news traders are usually best served by an ECN account: raw spreads keep the cost per trade low, and true no-dealing-desk routing avoids the requotes and execution restrictions that some market makers impose on very short-term strategies. The trade-off is the commission and occasional slippage during volatility. Long-term and position traders, who trade infrequently, feel spread cost far less and can reasonably use a fixed-spread market-maker account for its simplicity.