Losing Streak Calculator
A 50% win rate over 200 trades will very probably include a run of seven or eight losses. Enter your win rate and trade count to see the streak you should expect, and the odds of a streak of any specific length.
Streaks are normal, not evidence of anything
The expected longest run of losses over n trades is approximately log(n × W) ÷ −log(1 − W). At a 50% win rate over 200 trades that is about 6.6 — and the probability of hitting eight in a row somewhere in those 200 trades is roughly 53%.
Read that again, because it is the point of the page: a coin-flip strategy with a positive payoff ratio is more likely than not to produce an eight-loss run inside a normal year of trading. Nothing has broken. Nothing needs fixing. That is simply what randomness looks like at this sample size.
| Win rate | Expected longest streak (200 trades) |
|---|---|
| 30% | ≈ 11.5 |
| 40% | ≈ 8.6 |
| 50% | ≈ 6.6 |
| 60% | ≈ 5.2 |
| 70% | ≈ 4.1 |
Why this matters more than it sounds
Two failure modes come directly out of this table.
Abandoning a working system. Eight losses feels like proof the edge is gone. It usually is not — it is the expected outcome. Traders who rebuild their strategy after every long streak never accumulate enough trades for any edge to show.
Sizing that cannot survive the expected streak. If your normal risk is 5% and the expected streak is seven, the expected outcome includes a 30% drawdown. Not a tail event — the middle of the distribution. Check yours against the drawdown recovery calculator before deciding the size is comfortable.
Where the independence assumption breaks
The maths assumes each trade is an independent draw. Real trading violates this constantly: five long positions in correlated names is one bet, not five; a strategy tuned to a market regime loses repeatedly when the regime changes; and tilt after losses makes the next trade worse than the last. All three push actual streaks longer than the formula suggests. Treat the output as a floor.
Knowing your real win rate
Everything here scales off a number most traders estimate rather than measure — and estimate high. A win rate recalled from memory omits the trades that are unpleasant to remember. The only version worth putting in the field above comes from a record made before each outcome was known.
What a streak actually costs
The reason a streak is a sizing question rather than a luck question traces to Kelly's 1956 result: the growth-optimal fraction is finite, and betting above it converts an ordinary run of losses into a permanent loss of capital.[1]
The number is the easy part
Everything above is arithmetic, and anyone opening this page gets the same answer. What no calculator can settle is whether you took the trade on these terms, or are describing — afterwards — the version of it that worked out.
That is what a trade recorder is for: the trade committed before it resolves, timestamped and sealed on the spot, on a Merkle-anchored log a stranger can check without kappi's cooperation. The plan you typed here stops being a plan you remember having. $15/month, no free tier.
Sources
Frequently asked questions
How long a losing streak should I expect?
Approximately log(trades × win rate) ÷ −log(loss rate). At a 50% win rate over 200 trades, expect a longest run of about seven losses.
Is an eight-trade losing streak unusual?
Not at a 50% win rate over 200 trades — there is roughly a 53% chance of one occurring, making it more likely than not. It is the middle of the distribution, not the tail.
Does a long losing streak mean my strategy stopped working?
Usually not. Streaks of this length are the expected behaviour of any strategy with a win rate below about 60%. Judging a system on a streak is judging it on noise.
Why might my real streaks be longer than calculated?
The formula assumes independent trades. Correlated positions, regime changes and behavioural tilt after losses all produce longer runs than independence predicts.