A prop firm challenge gives you a set of rules and a target: reach the profit goal without breaking a loss limit, and the firm offers you a funded account. Expert advisors can suit rules like these, because they don't panic or chase losses. They can also fail a challenge in minutes if one setting ignores how the firm measures risk. This guide explains the common rule types, how they're usually calculated and how to set up an EA to stay inside them. Rules differ between firms and change over time, so always read your own firm's rules before you start.
How a challenge works
You pay a fee for an evaluation account of a stated size, such as the $50,000 account used in the examples below. You trade it under the firm's rules. Pass, and you move to a second phase or straight to a funded account, where you keep a share of the profits. Break a hard rule, and the account is usually closed straight away.
Two things make a challenge different from trading your own account. First, the limits are absolute: an account that goes $1 past the daily loss limit fails just as surely as one that goes $1,000 past it. Second, the rules use the firm's own definitions, which are often stricter than they first look. A misread rule can end a challenge as quickly as a bad strategy.
The rules you'll usually see
Names and numbers vary, but most challenges combine some of these rule types:
| Rule | What it means | What to check |
|---|---|---|
| Profit target | Reach a set gain, usually stated as a percentage of the starting balance. | Whether open trades count, and whether they must be closed to pass. |
| Maximum daily loss | You can't lose more than a set amount in one trading day. | The base it's calculated from, whether floating losses count and the reset time. |
| Maximum overall loss | Equity can never fall below a set floor. | Whether the floor is static or trails your highest balance or equity. |
| Minimum trading days | You must trade on a set number of separate days. | What counts as a trading day, such as opening at least one trade. |
| Consistency rule | No single day or trade may make up more than a set share of total profit. | How the share is worked out, and whether it applies to the challenge or only to funded accounts. |
| News restrictions | No trades opened or closed within a set window around major releases. | Which events count and how many minutes before and after. |
| Weekend holding | Positions may have to be closed before the market shuts on Friday. | Whether it applies to your account type. |
| Lot and leverage limits | Caps on lot size per trade, total exposure or leverage. | Limits on gold, indices and crypto, which are often lower than on currency pairs. |
How daily loss is measured
The daily loss limit deserves the closest reading, because the way it's measured is easy to miss. Most firms set a daily floor at a fixed reset time, often midnight on the firm's server or a time in a stated time zone, and fail the account if equity touches that floor before the next reset. Three details move the floor:
- The base. The limit may be a share of the initial account size, or a share of each day's starting balance.
- Balance or equity. Some firms start each day from the balance at the reset. Others use whichever was higher at the reset, balance or equity.
- Floating losses. At many firms, open losses count the moment they appear. Equity touching the floor fails the account even if the trade later recovers.
Worked example
Take a $50,000 challenge with a daily loss limit of 5% of the initial balance, so $2,500, measured from each day's starting balance (example rules):
- The day starts with a balance of $51,000. The floor for the day is $51,000 − $2,500 = $48,500.
- The EA closes two losing trades for a total of −$1,200. The balance is now $49,800.
- A third trade is open and showing −$1,400. Equity is $49,800 − $1,400 = $48,400.
- Equity is below $48,500, so the account fails, even though the closed loss for the day was only $1,200.
Under a rule that starts the day from the higher of balance and equity, a profitable open trade at the reset raises the floor. If the balance was $51,000 and equity $52,000 at the reset, the floor would be $52,000 − $2,500 = $49,500. Giving back that open profit would then use up part of the day's allowance.
The lesson for an EA: track equity, not only closed trades, and know the exact reset time. An EA's own “daily loss” input may count only closed trades or run on your local clock, and neither will match the firm.
Static vs trailing drawdown
The overall loss limit sets the lowest point equity may ever reach. It comes in two main forms:
- Static. The floor is fixed relative to the starting balance. On a $50,000 account with a 10% limit, it sits at $45,000 however much you make.
- Trailing. The floor rises with your highest balance, or your highest equity, by the same amount. Some firms stop the trailing once the floor reaches the starting balance.
Worked example
Same $50,000 account and a 10% limit, so $5,000. An open trade reaches +$3,000, then reverses and closes at breakeven. The balance never changed, but the floor may have:
| Drawdown type | Highest point recorded | Floor afterward | Room left at $50,000 |
|---|---|---|---|
| Static | Not used | $45,000 | $5,000 |
| Trailing on balance | $50,000 | $45,000 | $5,000 |
| Trailing on equity | $53,000 | $48,000 | $2,000 |
Under equity-based trailing, an EA that lets winning trades run and then gives the profit back shrinks its own room. Trailing stops, partial closes and earlier profit-taking all matter more under this rule. The drawdown calculator shows how quickly a losing streak at a given risk per trade eats into that room.
EA and strategy policies
Beyond the loss limits, firms set rules about how you trade. Policies on automated trading vary widely, and the same EA can be allowed by one firm and banned by another. Look for these in the terms and the FAQ:
- Whether EAs are allowed at all, and at which stage. Some firms allow EAs during the challenge but restrict them on funded accounts, or the other way round.
- Copy trading and trade copiers. Copying trades from another account, or between your own accounts, is restricted at some firms or has to be declared.
- Tick scalping and high-frequency trading. Strategies that open and close trades within seconds, or send very large numbers of orders, are banned at some firms, sometimes through a minimum holding time.
- Latency arbitrage. EAs that exploit delays in the price feed are prohibited at many firms.
- Hedging across accounts. Holding opposite positions on two accounts, at the same firm or at different ones, is prohibited at many firms.
- Grid and martingale. Some firms ban them outright. Where they're allowed, the loss limits make them hard to survive; our grid and martingale guide explains why.
- Third-party EAs used by many traders. When a widely sold EA places the same trades on many accounts, a firm may treat it as one strategy spread across many traders. Some firms limit or forbid this, or ask whether you use a third-party EA.
If a rule is unclear, ask the firm's support in writing before you start, and keep the reply. Save a copy of the rules as they stood when you bought the challenge, because terms change.
Configuring an EA for a challenge
The goal is easy to state: the EA's worst realistic day must fit inside the daily limit with room to spare, and its worst realistic losing run must fit inside the overall limit. Our risk management guide covers the general principles; here is how they apply to a challenge.
Size risk from the daily limit
Start with the EA's backtest. Find the most losing trades it took in a single day and how many trades it can hold open at once. Then work backward:
- Daily limit: $2,500 on a $50,000 account. The EA's worst backtest day had six losing trades.
- At 1% risk, or $500 a trade, six losses cost 6 × $500 = $3,000. That breaks the limit.
- At 0.5% risk, or $250 a trade, six losses cost 6 × $250 = $1,500. That leaves $1,000 for slippage, spread and a worse day than the test showed.
Check the overall limit the same way. At $250 a trade, a $5,000 overall limit allows 20 losses in a row before it's reached. The position size calculator turns a risk amount into lots for each symbol, and the risk of ruin calculator estimates how often a strategy with your win rate and reward to risk would reach a given limit.
Add equity protection
Run an equity protector that closes every trade and blocks new ones when the day's equity loss reaches a level inside the firm's limit, for example 4% when the firm allows 5%. Set it to measure equity, not balance, and to reset at the firm's reset time. Treat it as a backstop, not a guarantee, since price can jump past any level during news or a gap.
Stay out of news and weekends
If the firm restricts news trading, turn on the EA's news filter or set no-trade windows for the listed events, and check what the EA does with trades already open. If weekend holding isn't allowed, use the EA's Friday close setting, and set it well before the market closes, when spreads start to widen.
Don't chase the target
Raising risk to reach the profit target faster raises the chance of hitting a loss limit first. If the challenge has no time limit, there's no reason to hurry. If it does, check whether the EA's tested results could plausibly reach the target in that time at a safe risk. If they couldn't, that EA may not suit that challenge.
Plan for minimum days and consistency rules
An EA that trades rarely may reach the target before it has traded enough days, so plan to keep it running at low risk. Under a consistency rule, one big day can delay a pass. Say no day may exceed 40% of total profit (an example figure). A best day of $2,000 means total profit must reach $2,000 ÷ 0.40 = $5,000 before you can pass, even if the target was $4,000.
Finally, keep the EA running reliably. A home computer that sleeps or restarts overnight can leave trades unmanaged mid-challenge. Our VPS guide explains how to keep MetaTrader online around the clock.
Before you start
- Read the full rules, terms and FAQ, and save a dated copy.
- Write down exactly how daily and overall loss are measured: the base, balance or equity, floating losses, the reset time and its time zone.
- Confirm the firm allows your EA, its strategy type and any third-party EA, at both the challenge and funded stages.
- Check symbol details on the challenge server. Contract sizes, spreads, commissions and leverage can differ from your usual broker.
- Backtest with the challenge rules in mind, then run the EA on a demo with the same settings for at least a couple of weeks.
- Set the risk per trade, the equity protector, the news filter and the Friday close, and record every setting in a journal.
- Ask support in writing about anything that's unclear.
None of this makes a pass certain. It removes the avoidable ways to fail, so the result comes down to the strategy itself.