A Book vs B Book at Prop Firms

At a broker, the A book passes client trades to the market and the B book keeps the other side in house. Many prop firm funded accounts, including those at FTMO, are simulated, so a trader’s orders do not reach a market at all unless the firm chooses to copy them to a real account, and rewards are paid from the firm’s own revenue, which works like a B book. A smaller number of programmes copy trades into real accounts or move traders to live accounts, which works like an A book.

The broker terms, briefly

The labels come from retail brokerage. A broker running an A book sends client orders on to banks, market makers or an exchange, and earns from spreads and commissions. A broker running a B book takes the other side of client trades itself, so when a client loses the broker gains, and when a client wins the broker pays. Many brokers run both and move clients between books depending on how they trade.

Prop firms borrowed the terms, but the fit is loose, because on a simulated account there is no client money in the trade at all. The trader pays a fee, trades a simulated account, and the firm pays rewards under a contract.

How the terms map onto prop firms

The starting point is that evaluations, and many funded accounts, are simulated. FTMO states that all accounts it provides are demo accounts with fictitious funds, that trading is simulated only, and that FTMO companies do not act as a broker and do not accept deposits. Blueberry Funded describes its funded accounts as simulated, and Hantec Trader runs all its accounts on simulated capital.

Regulators have drawn the same line. The Czech National Bank, the central bank and financial regulator in the country where FTMO’s companies are registered, published an opinion that simulated trading on a demo account, with no real orders executed or settled, is not an investment service and does not need its permission. The same opinion expressly leaves out business models where orders placed on the demo account are mirrored onto a real trading account, which is the prop firm version of an A book.

So a prop firm has three broad choices once a trader is funded:

• Keep everything simulated and pay rewards from revenue, mainly evaluation fees. Economically this resembles a B book: the firm’s cost is the rewards it pays, and a losing trader costs it nothing beyond the fee already collected.
• Copy selected traders into real accounts, so that the firm’s own capital follows the trader’s decisions. This resembles an A book, and the firm earns its share of real profits.
• Move traders to live accounts, often after a run of payouts, where orders reach the market through a clearing broker.

Worked example: one trader, two models

Take a made up $100,000 funded account with a 10% maximum loss, an 80% split and a $550 evaluation fee. The figures are an illustration.

The table shows why the model shapes behaviour. Under the simulated model, the firm’s risk is paying too many rewards relative to fee income, so it cares about pricing, pass rates and rules that limit very large or very fast profits. Under the copied model, the firm’s risk is real market loss, so it cares about which traders it copies and how consistently they trade. Neither model is improper in itself. What matters is whether the firm describes accurately which one it runs.

How firms differ

A few programmes publish how real capital enters the picture:

• Axi Select reverses the usual order. Traders deposit at least $500 of their own money and trade it live at Axi, and once they meet the entry conditions Axi opens a separate Allocation Account funded with its own capital and copies their orders into it. Axi’s terms warn that copied orders may not receive the same fill price.
• Topstep runs an Express Funded Account and a Live Funded Account, and states that 30 winning days in the Live Funded Account unlock daily payouts of up to 100% of profits.
• DayTraders.com pays 100% of simulated profit on its Pro and Straight to Funded accounts but 80/20 on live accounts, which pay daily once the drawdown has locked.
• Funded Futures Family can move traders to a live account on Rithmic after $5,000 in approved payouts, and its live accounts add a daily loss limit that its simulated funded accounts do not have.
• Hola Prime Futures offers invitation only live accounts to traders with at least ten payouts totalling $50,000 or more.

Disclosure helps readers judge the simulated model too. Hola Prime publishes a 35% pass rate for customers who traded an evaluation between November 2024 and May 2025, which tells you how many buyers reach the funded stage there.

Why the model was at the centre of a regulator’s case

In its August 2023 complaint against Traders Global Group, the company behind My Forex Funds, the CFTC alleged that customers were told they traded against third party liquidity providers when the firm itself was the counterparty to substantially all customer trades, and that payments to successful traders came mainly from other customers’ fees. The allegations were not proven in court: in May 2025 a special master appointed by the court recommended dismissing the complaint with prejudice and sanctioning the CFTC for false statements to the court. The episode still shows where scrutiny falls, which is on the gap between what a firm says about its model and what it does.

What the model means for you

For a trader, the model affects three practical things. The first is payout reliability: under a simulated model, rewards depend on the firm’s fee income staying ahead of what it pays out, so a firm that sells heavily discounted evaluations while paying generous splits has less room for error. The second is rule design: rules that limit single large days, very short trades or trading around news protect a firm that pays from revenue, and you should expect them and read them. The third is execution: a simulated fill is not a market fill, so a strategy that relies on exact prices may behave differently if you move to a live or copied account. None of these is a reason to avoid prop firms, but each is a reason to read the terms before you buy.

Common mistakes

• Assuming a funded account means real capital. Read the terms for the words simulated, demo or fictitious.
• Treating a B book style model as proof of a scam. Simulated accounts are normal; misdescribing them is the problem.
• Expecting identical fills after a move to live trading. Real execution adds slippage and, as Axi warns, copied orders may fill at different prices.
• Ignoring rule changes at the live stage. Daily loss limits, contract limits and payout terms can all change.
• Building strategies around simulation quirks. Latency and arbitrage tactics that exploit a simulated feed are widely prohibited.

Checklist

• Find the firm’s statement on whether accounts are simulated.
• Check whether and how traders move to live or copied accounts.
• Read how the rules and split change at that stage.
• Look for published data such as pass rates or payout totals.
• Compare the firm’s marketing with its terms; they should say the same thing.

For how fees and rewards fit together, read how prop firms really make money and how prop firms are reinventing their business models. Whether a given firm deserves your fee is covered in are prop firms legit, and the regulatory side in prop firm regulation by country. Browse futures firms for live account routes and the industry section for more.