The signature: size follows results, not the system
The numerical test is simple and requires no self-judgement: compute your average position size after three consecutive winners and compare it with your overall average size. If the first is more than 20% higher, your size follows recent results rather than your rules.
The irony is that this happens at the worst possible moment: a winning streak does not raise the probability of the next trade winning if trades are independent, so you increase risk at a point where the odds have not changed. See risk per trade.
When it is not overconfidence
Raising size is not always a bias, and the distinction matters so you do not correct sound behaviour. A larger size is justified in two clear cases:
- Account growth — 1% of $1,200 is more in dollars than 1% of $1,000, while the percentage is unchanged. That is holding risk constant, not raising it.
- A tighter stop — a closer stop permits a larger size at the same percentage; that is arithmetic, not a decision.
The decisive test: if the percentage held constant you were disciplined, however many lots changed. If the percentage itself rose after wins, that is the signature.
Why advice fails, and what works instead
A bias is not fixed by advice, because in the moment it does not feel like a bias — it feels like a sound decision based on a correct reading. This is why "be disciplined" and "control your emotions" change nothing: they ask you to notice what is designed not to be noticed.
The practical alternative is for each bias to have a measurable signature in your trade record: a number you compute yourself that confirms or rules it out. This family uses the same reference account as the other risk pages — $1,000 risking 1%, or $10 a trade — so every example is directly comparable.
The limits of these pages are explicit: they describe trading behaviour and decisions, not a psychological state and not a medical diagnosis.
A worked example
On the reference account: three winners lifted the balance to $1,061. Risking 1% now means $10.61 — a natural increase.
But the trader raises risk to 3% "because the read is clear", or $31.83. The next trade loses and erases roughly everything three winners accumulated.
Neither the system nor the odds changed; only the percentage did. Repeated, this raises risk of ruin substantially while the edge stays the same — because an ordinary losing streak becomes fatal at a higher percentage.
Common mistakes with this term
- Raising the risk percentage after a winning streak, when the odds on the next trade did not change.
- Confusing a larger size from account growth with one from confidence; the first holds the percentage, the second raises it.
- Reading a winning streak as improved skill without a sample large enough to support it.