I previously posted the differences between forex/CFD order execution versus real futures order execution in several Forum threads, where there was quite a bit of confusion on the subject. Recently, I obtained detailed information that better explains those differences─directly from the Chicago Mercantile Exchange (CME). The following excerpts are quoted from the CME website:
Retail traders in the forex and CFD space operate under very different mechanics. Unlike organized exchanges, there is no centralized order book that aggregates all buy and sell interest. Instead, brokers typically use one of two models:
- Market maker (B-book): The broker internalizes client orders and acts as the counterparty.
- Aggregator (A-book): The broker streams prices from multiple liquidity providers but still manages client execution internally.
Either way, when you place what looks like a “limit order” on retail platforms operating the B-book or A-book models, you are not joining a global queue of buyers and sellers. Your order is simply an instruction stored by the broker: “Execute my trade if the price stream you show me reaches this level.”
...
At first glance, the difference may seem technical, but it has profound implications for trading strategies and expectations:
- In centralized markets, limit orders are a cornerstone of market microstructure. They create liquidity, establish price discovery, and allow even small participants to place themselves “in the market.”
(https://www.cmegroup.com/articles/2026/the-limits-of-limit-orders-in-retail-fx-cfd-trading.html).
In that CME article, the differences are demonstrated by using execution of limit orders as an example. Those are the core differences between OTC (over the counter) forex/CFD broker-dealers versus centralized exchange futures.
I would also add that some forex/CFD broker-dealers use a hybrid combination of a B-book and an A-book depending on the symbol and/or position size traded.
U.S. forex broker-dealers tend to use a triple hybrid of a B-book, an A-book, and STP (straight through processing─to the wholesale interbank market)... again, depending on the symbol and/or position size traded. This is due to the fact that the U.S. NFA (National Futures Association) requires all U.S. forex trades to ultimately be cleared in the interbank market. Therefore, CFD's are banned in the U.S.
To be clear, forex trade execution must be provided equally in the U.S. It is illegal for a U.S. broker-dealer to process losing traders one way and profitable traders another way. Based on my own experience, I can tell you that it sometimes happens nonetheless.
