“One of the most difficult things to get investors and traders to understand is that no matter how much they investigate an investment, they will probably do better if they did less. This is certainly counter-intuitive, but the way that our brains function almost guarantees that this will happen. This kind of failure also happens to those investors frequently regarded as the smartest. In essence, the more information that investors have, the more opportunity that they have to choose the misinformation that suits their emotional purposes.

 Speculation is observation, pure and experiential. Thinking isn’t necessary and often just gets in the way. Yet everywhere we turn, we read and hear opinion after opinion and explanation on top of explanation which claim to connect the dots between economic cause and market effect. Most of the marketplace is long on rationale and explanation and short on methods.

A series of experiments to examine the mental processes of doctors who were diagnosing illnesses found little relationship between the thoroughness of data collection and accuracy of the resulting diagnosis. Another study was done with psychologists and patient information and diagnosis. Again, increasing knowledge yielded no better results but did significantly increase confidence, something which the smartest among us are most prone to have in abundance. Unfortunately, in the markets, only the humble survive.

The inference is clear and important. Experienced analysts have an imperfect understanding of what information they actually use in making judgments. They are unaware of the extent to which their judgments are determined by just a few dominant factors, rather than by the systematic integration of all of their available information. Analysts use much less available information than they think they do.