Is a win due? What a losing streak does and does not tell you
hypothesess.com, AI-assisted writing ยท
Overview
Is a win due? Short answer: no. After five losses in a row, a strategy that wins 55% of the time still wins its next trade 55% of the time. The streak changes nothing about the next trade. What it should change is your idea of how long losing streaks get: far longer than feels possible, even for a strategy that works. Over 200 trades at 55%, the longest losing streak is typically six, and one run in six reaches eight or more [1].
What happens right after five losses
Play 200,000 trades of a 55% strategy and, every time the last five trades all lost, write down whether the next one won. That window comes up about 3,700 times in 200,000 trades [1]. The next trade wins about 55% of those times, give or take the noise of a few thousand tries [1]. Not more, because the market does not keep a ledger. Not less, because five losses are what a 55% strategy produces in the ordinary course of things.
The feeling that a win is due is the gambler's fallacy, and it survives because the long-run average really does settle at 55%. It gets there by swamping the early streak with thousands of later trades, never by paying losses back.
Then why does a streak feel like a signal?
Because people expect randomness to look tidy. Asked to write down 100 coin flips, most people switch between heads and tails too often and avoid long runs; a made-up row rarely holds more than three alike. Real randomness is lumpy. In 100 real fair flips, the longest run of one side is usually seven, and a run of six or more appears in about four rows out of five [1]. A row with no run longer than three is almost impossible: about three in ten thousand [1].
So the tell between a real coin and a faked one is the longest run. The real one has a streak that looks wrong. That same instinct, applied to a trading record, reads an ordinary losing run as news.
How long can a losing streak get on a strategy that works?
This is the useful question, because the answer tells you when to stop worrying and when to start.
Over 200 trades at a 55% win rate, the longest losing streak is six in the typical run; one run in ten reaches eight, and about one in six reaches eight or more [1]. A run of ten or more losses happens in about one record in 28 [1]. Stretch the record to 1,000 trades and the typical worst streak grows to eight, with one run in ten reaching ten [1]. More trades mean longer worst streaks, slowly: doubling the trades adds about one loss to the longest run.
A stronger edge shortens the streaks but does not remove them. At 65% over 200 trades the typical worst streak is four, and about one record in thirteen still shows seven or more losses in a row [1].
Nerd corner
If the strategy's edge does not change, each trade is independent of the last, so the chance of a win after five losses is the chance of a win, full stop. The law of large numbers says the share of wins drifts toward 55% over many trades; it says nothing about the next one.
For n trades with loss rate q, the longest losing streak is usually close to L ≈ ln(n × (1 − q)) / ln(1 / q) [2]. At 200 trades and q = 0.45 that gives 5.9, against an exact median of six [1]. The figures above come from the exact distribution of the longest run, computed by stepping through the trades one at a time and tracking the current run length, not from the approximation.
One exception matters: a long streak can also mean the edge is gone because the market changed. The streak alone cannot tell you which. A streak well past the "one run in ten" figure for your record is the time to look.
| Figure | Value | Where it comes from |
|---|---|---|
| Typical longest losing streak, 200 trades at 55% | 6 losses | exact distribution of the longest run [1] |
| Longest losing streak reached by 1 run in 10, 200 trades at 55% | 8 losses | the same [1] |
| Chance of a streak of 8 or more, 200 trades at 55% | 16.5% | the same [1] |
| Typical longest run of one side, 100 fair flips | 7 | the same, both sides [1] |
| Chance a fair coin's next flip is heads after 7 tails | 50% | independence |
Check yourself
You flip a fair coin and get tails seven times. What is the chance of heads next? 50%. The coin has no memory; seven tails in a row is a 1-in-128 event that has already happened, and the next flip does not know about it.
Over 200 trades at 55%, is a run of seven losses a sign the strategy broke? Not on its own. The typical worst streak in such a record is six, and about one record in three contains a run of seven or more [1]. A seven-loss run is ordinary.
Your win share will approach 55% over many trades. Does that mean wins must catch up after a streak? No. The share approaches 55% because later trades outnumber the streak, not because wins become more likely after it.
An illustration, not trading advice. A lab notebook entry for hypothesess.com, written with AI and checked by hand; every figure was computed from the exact distribution of the longest run, and the box above recomputes the rough ones for your own numbers.