You can have a genuinely profitable system and still fail an evaluation — not on drawdown, but because the way it makes money sits on your firm’s banned list. Passing the numbers is worthless if the method gets your payout voided.
Here’s what firms tend to prohibit, why, and how to avoid tripping a rule you didn’t know applied to you.
Why firms ban certain strategy types
A prop firm isn’t judging whether your strategy is clever. It’s judging whether your profit came from a repeatable trading edge it can trust on a funded account, or from exploiting the firm’s pricing, execution, or account structure.
Bans cluster around a few motives:
- Non-repeatable exploits — profit that comes from latency, a stale quote, or a bonus/structure quirk rather than from reading the market.
- Hidden tail risk — methods that show smooth equity curves right up until they detonate.
- Cost to the firm’s liquidity provider — behavior that gets the firm flagged or throttled upstream.
Understanding the motive is the shortcut: if a technique makes money in a way the firm can’t picture funding at scale, assume it’s restricted until the rulebook says otherwise.
Martingale and grid: why averaging into losers is flagged
Martingale (doubling size after a loss to recover on the next win) and grid (stacking orders at intervals as price moves against you) share a fatal shape: they produce many small wins and rare, catastrophic losses. On an evaluation that looks like a beautiful equity curve — until the one run that blows through the drawdown floor.
Firms flag these because the smooth curve is a lie about the underlying risk. Even where the mechanic isn’t named explicitly, the behavior gets caught: rapidly increasing position size after losses, or a cluster of same-direction adds into a falling position, is the signature reviewers look for. The deeper problem is that averaging into losers usually masks negative expectancy — the strategy only “works” because you haven’t hit the bad tail yet. Run your real numbers through the expectancy calculator; if the edge is only positive when you exclude the worst outcomes, it isn’t an edge, it’s a fuse.
HFT, latency, and tick-scalping restrictions
Firms also restrict strategies that lean on speed and infrastructure rather than market read:
- High-frequency trading (HFT) — automated systems firing hundreds or thousands of orders, often disallowed outright.
- Latency / arbitrage exploits — profiting from the gap between the firm’s feed and a faster reference price.
- Tick-scalping — capturing sub-second moves or fractions of a pip, sometimes caught by a minimum hold time rule that voids trades closed too fast.
The tell here is a rule you might not read as a strategy ban at all: a minimum time-in-trade, a cap on trades per second, or a limit on how much of your profit can come from ultra-short holds. These exist specifically to disqualify speed-based methods. If your system’s edge lives in the first few seconds after entry, verify the hold-time rules at your program before you scale it.
Arbitrage, cross-account hedging, and copy abuse
The last cluster is about gaming the account structure rather than trading a market:
- Arbitrage across venues, or between the firm’s pricing and an external feed.
- Cross-account hedging — opening opposite positions on two accounts so one is guaranteed to pass while the other absorbs the loss. Firms treat this as an attempt to convert a coin-flip into a “free” funded account, and it’s a common instant disqualifier.
- Copy abuse — running the same trades across many accounts to farm payouts, or copying from a signal source shared by other funded traders, which can look like coordinated group trading.
| Strategy type | Typical status | Why it’s flagged |
|---|---|---|
| Martingale / grid | Often banned | Hidden tail risk, negative expectancy |
| HFT / tick-scalp | Often restricted | Speed exploit, not market edge |
| Latency arbitrage | Almost always banned | Exploits feed pricing, not the market |
| Cross-account hedge | Almost always banned | Converts a coin-flip into a payout |
Legitimate copying of your own strategy across your own accounts is usually fine and is a normal way to scale — the line is drawn at coordinated hedging, shared signal groups, and using copies to manufacture guaranteed passes. Because that line is easy to cross by accident, read your program’s copy policy in full; the distinction is covered in more depth in the copy-trading rules guide.
Reading the fine print before you deploy a system
Prohibited-strategy rules are the least standardized part of any rulebook and the most quietly updated. Before you commit a system to a funded account:
- Search the rulebook for the behavior, not just the name. “Martingale” may not appear, but “increasing size to recover losses” might.
- Check the hold-time and order-frequency rules — these silently outlaw fast strategies.
- Confirm the copy and hedging policy if you run more than one account.
- Re-read on renewal. A method that was fine last quarter can be restricted this one.
The policies at MyFundedFX, FunderPro, and The Funded Trader each phrase these bans differently, so don’t assume one firm’s wording carries to another. The safest system is one whose edge is a real, measurable read on the market — the kind you can defend with a positive expectancy over a real sample, not one that depends on a loophole the firm hasn’t closed yet.
Related: expectancy calculator · trading expectancy explained · Shibiki for The Funded Trader