Every order a client sends puts a question on your desk: pass the risk to a liquidity provider, or keep it? That single decision — repeated thousands of times a day — is the core of broker economics. Answer it crudely and you either give away your margin or carry exposure that can hurt you in one bad session. Answer it well and both sides of the book work for you.
The old caricature — "A-book brokers are honest, B-book brokers bet against clients" — misses how modern desks actually run. Here is the real mechanics of both models, and how a hybrid, per-trader approach became the professional standard.
A-book: Hedging the Flow
In the A-book model, your broker hedges each client order with a liquidity provider: the client buys, you buy the same exposure from your LP. Your P&L comes from the spread markup and commissions, not from the client's result — you are a conduit, earning a toll on volume.
- Strength: near-zero market risk. A client's winning streak costs the LP, not you. Revenue is stable and scales with volume.
- Cost: you pay the LP's spread on every trade, so your margin per trade is thin — and small, noisy retail flow is often more expensive to hedge than it's worth.
B-book: Internalising the Flow
In the B-book model, your broker takes the other side internally. No hedge is placed; the client's loss is your gain and vice versa. This is not a scandal — it is what market-making has always been. Retail flow is, in aggregate, uncorrelated and short-horizon, and internalising it typically earns both the full spread and much of the flow's trading result.
- Strength: materially higher revenue per lot — you keep the spread and avoid LP costs.
- Cost: you carry market risk. A skilled trader, a one-sided book during a trend, or a news spike can produce sharp drawdowns if exposure isn't watched and capped.
The honest framing: A-book converts market risk into a thin, stable toll; B-book converts spread income into a wider but riskier margin. Neither is virtuous or sinful — the professional question is which flow belongs where.
The Hybrid Standard: Decide per Group, per Instrument, per Trader
Almost no serious broker is purely one or the other. The modern desk runs a hybrid: internalise the broad retail flow that behaves like noise, hedge the flow that behaves like signal. What separates platforms is the granularity at which that split can be made. In eTrader Broker, routing is decided at three levels:
- Per group — a VIP group of large, sophisticated accounts routes A-book; a standard retail group warehouses B-book. Groups already drive your spreads, markups and leverage, so routing follows the same segmentation.
- Per instrument — internalise majors where your book is deep and offsetting, hedge thin crosses, crypto or indices where inventory risk is expensive.
- Per trader — the decisive level. A consistently profitable or high-risk trader is routed A-book individually, while the rest of their group stays internalised. No group reshuffling, no blunt instruments.
This granularity is what turns routing from a policy into a risk-management tool. And it can go further still: the built-in intelligent engine scores every trader and order in real time and routes flow automatically — profitable or toxic flow hedged to your LPs, the rest warehoused — switching dynamically as behaviour changes. That autopilot mode has its own deep dive in intelligent A/B routing.
Exposure and P&L, Monitored Live
A B-book without live exposure monitoring is a slow-motion accident. The discipline that makes internalisation safe is seeing, at all times, what the book is carrying: net exposure per instrument, aggregate P&L on warehoused flow, and the share of flow routed A-book. In eTrader Broker, exposure and P&L are monitored live on the dashboard — the same console where LPs, groups, leverage and instruments are managed — so the routing decision and its consequences sit on one screen.
Live visibility changes behaviour in practical ways:
- Concentrated one-way exposure on an instrument is a signal to hedge the excess now, not at tomorrow's review.
- A trader whose warehoused P&L keeps costing you is a candidate for individual A-book routing today.
- LP fill quality and hedge costs are visible against the exposure they remove, so you can judge whether each hedge is earning its keep.
The broader monitoring stack — groups, leverage control and the dashboard's live metrics — is covered in broker risk management.
Choosing Your Starting Mix
| A-book | B-book | Hybrid (per trader) | |
|---|---|---|---|
| Market risk | Minimal | Full book exposure | Capped — toxic flow hedged |
| Revenue per lot | Markup + commission only | Spread + flow result | Optimised per flow type |
| LP costs | On every trade | None | Only where hedging pays |
| Needs | LP relationships, volume | Live exposure monitoring, capital buffer | Granular routing + live P&L |
A young broker typically starts B-book-weighted — flow is small, hedging costs bite, and the included 70ms feed plus dashboard controls are enough to run safely — then adds LP relationships and shifts flow A-book as volume and concentration grow (see liquidity providers 101). The point of a granular platform is that this evolution is a settings change, not a re-platforming. You can inspect the routing controls yourself in the live demo.
"Routing isn't a moral choice, it's a risk choice — made per group, per instrument, per trader, with live eyes on exposure."
— Roman Onta, Executive Director, Broker CRM & UI/UX
Key Takeaways
- A-book trades margin for safety; B-book trades safety for margin. Every serious desk runs both.
- The professional standard is routing decided per group, per instrument and per trader — granularity is the whole game.
- B-book is only safe with exposure and P&L monitored live, on the same dashboard where routing is controlled.
- Start B-book-weighted, hedge as flow grows — on eTrader Broker that evolution is configuration, not a rebuild.
Frequently Asked Questions
Is B-booking Client Orders Legal?
Internalising order flow is standard market-making practice and is permitted under most regulatory regimes, subject to your licence's conduct and disclosure obligations. What matters is running it with proper risk controls and complying with your jurisdiction's rules — your firm's compliance responsibility, since Singuard provides the software only.
Can One Trader Be Routed Differently from Their Group?
Yes. In eTrader Broker, routing is decided per group, per instrument and per trader — so a single consistently profitable account can be hedged A-book while the rest of its group stays internalised, without moving anyone between groups.
What Is Intelligent Auto-Routing?
A built-in risk engine that scores every trader and order in real time and routes the flow for you — profitable or high-risk flow hedged to your LPs, the rest warehoused B-book, switching dynamically as behaviour changes. See the full write-up in intelligent A/B routing.