Behavioral Finance

Cognitive Biases in Investing: What Is Costing You Returns

Investment underperformance is rarely caused by bad investment selection. It is almost always caused by a small set of well-documented cognitive biases that pro…

Behavioral Finance

Cognitive Biases in Investing.

The specific thought patterns that consistently produce the worst investment outcomes.

Investment underperformance is rarely caused by bad investment selection. It is almost always caused by a small set of well-documented cognitive biases that produce predictable, avoidable errors.

1.5%average annual return gap between the market and what the average investor actually earns — almost entirely explained by behavioral errors, not investment selection

The Situation

The Gap Between Markets and Investors

The S&P 500 has historically returned approximately 10% annually. The average equity fund investor has earned approximately 8.5% annually over the same periods. That 1.5% gap is not caused by poor fund selection — it is caused by investor behavior: buying after gains, selling after losses, and reacting to news in ways that systematically damage long-term outcomes.

The market offers a return. Behavior determines how much of it you actually receive.
— Worthune Decision Framework

You've sold investments during downturns and bought during rallies, underperforming a simple buy-and-hold strategy
You're drawn to investments in industries or companies you're personally familiar with
Your portfolio is concentrated in your employer's stock or in sectors you follow closely

About This FinBook

The average investor underperforms the market by 1.5% annually — not from bad picks, but from cognitive biases. Learn the most costly biases and how to counteract them.

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