Losing Streak Probability Calculator

When a losing streak arrives, it feels like proof that something has broken. Often nothing has. Even a strategy that works will string together losses now and then, and the calculator shows how often that should happen at your win rate, so you can tell the difference between bad luck and a real change.

There are two questions to ask. The first is the chance that the next several trades all lose, which is simply the loss rate multiplied by itself that many times. The second is the chance that, somewhere in a stretch of trades, you will see a run of that length at least once. The second is far larger than people expect, because there are many places in a long stretch where a run could begin.

At a 50% win rate, six losses in a row has a probability of about 1.6% for any particular six trades, but over a hundred trades the chance of seeing a run of six somewhere is a little over one in two. Streaks are not an anomaly of a long enough record; they are a feature of it.

This matters for how you respond. Knowing that a streak of a given length is normal for your win rate lets you stay with a plan that is still working. Knowing that your streak is far beyond what chance would produce is a reason to review it. To see what you actually do during streaks, use the losing streak analyzer.