How much should you risk per trade on a prop firm evaluation?

Divide the maximum drawdown by the number of straight losing trades you want to be able to take. On a $2,500 limit, surviving ten losers in a row means risking no more than $250 per trade, and less if the drawdown trails your highest balance.

How likely is a long losing streak?

For a strategy that wins half its trades, any particular run of ten trades has a 1 in 1,024 chance of being all losers. Over hundreds of trades there are hundreds of overlapping runs of ten, so the chance of hitting one somewhere is far higher.

Should you increase size to recover a drawdown faster?

No. Raising size after losses shortens the streak that ends the account. On a $2,500 limit, doubling from $250 after each loss means the fourth straight loser finishes the evaluation, against ten at a flat $250.

Position Size for the Losing Streak You Have Not Had Yet

The rule page says maximum drawdown: $2,500. That line matters more than the profit target, the daily loss limit or anything on the chart, because it sets the number of mistakes, bad fills and plain bad luck you are allowed before the evaluation is over. Everyone who trades long enough meets a losing streak. Position size is the only thing that decides how long a streak the account can take.

Rule: size from the drawdown limit

Start with the limit and work backwards. On a hypothetical $50,000 evaluation with a $2,500 maximum drawdown, risk per trade sets the number of straight losers it takes to reach the limit.

Five losers in a row can fit inside one bad week. Ten takes more bad luck. Neither number measures skill. They are the length of the rope.

Same trader, same entries, same exits. At $500 a trade the evaluation ends on the fifth consecutive loss; at $250 the trader is still there after the ninth, still following the plan, with room left for the streak to end the way streaks do and for the next winner to start filling the hole.

The reason for the rule: the drawdown limit is fixed, and the profit target only matters to a trader who is still in the evaluation. Size for the target and the first bad run can end it. Size for the limit and it lives to see the target.

Rule: expect the streak, whatever the win rate

A strategy that wins half its trades feels safe. Test that feeling. The sum below is pure probability, with no claim about any real strategy.

One in 1,024 sounds remote. It is the chance for one particular run of ten trades, though, and across a few hundred trades there are a few hundred overlapping runs of ten, each with its own small chance, so a long streak somewhere in the record stops being remote and starts being the kind of thing you should plan for. Shorter streaks are more common again. Run your own win rate and trade count through the losing streak calculator.

The reason for the rule: the worst run in your record is only the worst run so far.

Rule: in your own account, risk a fixed fraction

Without a firm’s hard limit, the same logic works on a percentage. Risk a fixed share of the current balance on each trade, and the dollar risk shrinks as the account shrinks.

At 1%, ten losers cost $4,781. At 2%, they cost $9,146. That is a little under double, since each loss at 2% shrinks the base the next one is taken from. The recovery is where it hurts. From $40,854, getting back to $50,000 takes a gain of about 22%. From $45,219 it takes about 10.6%.

The reason for the rule: a fixed fraction brakes on the way down. Fixed dollars never do.

Rule: cut size after a set loss

Decide in advance what loss triggers a cut. Say you start the $2,500 evaluation at $250 a trade and halve to $125 once you are down $1,000.

The reason for the rule: a streak can mean your read of the market is off, and the cut buys time for that read to recover before the limit arrives.

Rule: never raise size to win it back

Doubling after a loss is the surest way to shorten the rope. Start at $250, then $500, then $1,000. Three losers have cost $1,750, and the fourth trade at $2,000 risks far more than the $750 left, so the fourth straight loser ends the evaluation where flat sizing at $250 would have taken ten to reach the limit.

The urge arrives at the worst moment: several losses in, the floor close, one big winner looking like the quickest way back to even. It is also the quickest way out of the evaluation. Write the rule down before the streak starts, when it costs nothing to agree with.

The reason for the rule is in that sum. How the firm handles payouts and the drawdown cushion afterwards is covered in a prop firm payout comes out of your drawdown cushion, and the entry on minimum trading days covers the rule on how many days you must trade before an evaluation can pass, which is one reason a streak cannot simply be waited out.

Size for the streak, and the limit stops being the threat

The position holds wherever there is a floor. A firm’s drawdown limit is one. So is the amount you can lose before you stop trading. It weakens only for a trader with a long record and a win rate high enough that long streaks really are rare, and even then the record is a sample, and a sample that has not yet produced its worst run is exactly the one that tempts a trader to size up. Pick the streak you want to survive, divide the limit by it, and trade that size.