Cognitive Bias
Gambler's Fallacy — Definition, Examples, How to Fix
Believing that past random outcomes change the probability of future ones — "I've had 5 losses, so a win must be coming."
What it is
The gambler's fallacy is the belief that streaks must self-correct in random sequences. In trading it shows up as: "I've lost 5 trades in a row, so the next one is more likely to win." But each independent trade has roughly the same probability as the last. The fallacy leads traders to size up after a losing streak ("the recovery trade is here") — which is exactly when they should be sizing down.
What it looks like
- Doubling size after 4 consecutive losses because "the streak has to end."
- Taking a marginal setup after a losing morning to "balance out the day."
- Believing that "the win-rate has to revert" within a single session.
Why it costs you money
Gambler's-fallacy sizing is the opposite of what should happen during a losing streak — adding more risk to a state where the trader is clearly off rhythm. The realised loss when this triggers is often 3-5x normal trade size.
How TradeSaath detects this
TradeSaath compares position-size variance against your win/loss streak state. Sizing up after 3+ consecutive losses is flagged.
How to fix it
- Size based on plan, not on streak. Cap size during drawdown.
- After 3 consecutive losses, reduce size by 50% or stop trading.
- Track the win rate of trade #N+1 after N consecutive losses — usually unchanged.
- Replace "the recovery is coming" with "each trade is independent."
Related
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