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Create AccountLosing Streak Calculator
See how long a losing run to expect at your win rate, and what it costs the account.
Your Result
The calculation runs in your browser. Rates used for currency conversion are indicative — check your broker for the exact figure.
A losing streak is not a sign that a strategy has stopped working. At a forty percent win rate, a run of eight losses is not unusual over two hundred trades — it is close to what should be expected. Traders abandon working strategies during exactly these runs, because nobody told them what normal looks like.
This gives two numbers. The longest run to expect over the period, and the chance of a specific run you name. Both come from the win rate alone, treating trades as independent, which is the standard assumption and close enough to be useful.
When to use it
- Before starting a strategy, so the first bad run is not a surprise.
- During a losing run, to see whether it is inside normal or genuinely unusual.
- When choosing a risk percent, to see what a normal run does to the account.
- Before taking a prop firm challenge, where a normal run can breach a drawdown rule.
The chance of a run of losses is the loss rate multiplied by itself once per loss.
Loss Rate = 1 − Win Rate
Chance of N losses in a row = Loss Rate ⁿ
Expected longest run ≈ log(Trades) ÷ −log(Loss Rate)
Drawdown = 1 − (1 − Risk)ᴺ- Trades are treated as independent, as a coin is. Real trading is not quite independent — a bad market phase produces clustered losses — so real streaks tend to run slightly longer than this.
- The expected longest run is the typical worst run over that many trades. Longer runs happen; this is the middle of the distribution, not a ceiling.
- The cost assumes each loss is a full stop and risk is a fixed percent of the current balance, so losses compound downward and the total is slightly less than risk multiplied by the streak.
- The recovery figure is larger than the drawdown, always. Losing twenty percent needs twenty-five percent to get back.
A 40% win rate over 200 trades, risking 1% each, checking the odds of eight losses in a row.
Working: at a 40% win rate, six trades in ten lose. Eight losses in a row is 0.6 to the eighth power, about 1.7% on any given attempt, but across two hundred trades a run of around ten is what should be expected. At one percent risk that is a drawdown near ten percent, which is survivable — at three percent risk the same normal run takes a quarter of the account.
Does a long losing run mean my strategy is broken?
Not by itself. Compare the run you are having with the run this predicts. If eight losses is what two hundred trades should produce, eight losses tells you nothing except that the maths worked. A run well beyond the expected length is worth investigating.
Why does the expected run get longer with more trades?
Because you are giving the streak more chances to happen. The chance of eight losses on any particular attempt does not change; the chance of it occurring somewhere in a thousand trades is much higher than in fifty.
Are real streaks longer than this?
Usually slightly, yes. The formula treats trades as independent, but losses cluster — a strategy that suits trending markets loses repeatedly through a range. Treat this as a floor rather than a limit.
How does this help with a prop firm challenge?
Directly. A normal losing run at your win rate has to fit inside the firm’s overall drawdown limit. If it does not, the account will fail on ordinary trading rather than on a mistake, and the risk per trade is the only thing you can change.
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