00 Behavioral Finance

Overconfidence Bias in Trading

A well-documented pattern in behavioral finance, and a specific one worth recognizing in your own trading.

Short answer

Overconfidence bias is the tendency to overestimate the accuracy of your own judgment and predictive ability, and in trading it typically shows up after a winning streak, as increased size, increased frequency, and reduced attention to risk management.

01 Why it happens

A winning streak is often mistaken for skill improving in real time

A run of good results can come from genuine skill, from favorable market conditions, or from luck, and it's genuinely hard to tell the difference from inside the streak. Overconfidence bias is the tendency to assume the first explanation by default, which leads to taking on more risk exactly when a string of variance-driven wins is statistically due for a correction.

02 What this looks like

Where it shows up in real trading

Naming the bias isn't the same as catching it

See the pattern in your own trades.

PnL App logs the decisions behind every trade, so a bias like this one shows up as a real, measurable pattern instead of a feeling you can rationalize away.

03 Related

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