People are, by and large, quite poor at judging correct absolute values but are astute about determining relative values. Psychologists call this coherent arbitrariness, which suggests that individuals are coherent when they compare prices on a relative basis but arbitrary when those prices are considered versus fundamental value.
Michael MauboussinHumans have a strong desire to be part of a group. That desire makes us susceptible to fads, fashions, and idea contagions.
Michael MauboussinWe have no control over outcomes, but we can control the process. Of course, outcomes matter, but by focusing our attention on process, we maximize our chances of good outcomes.
Michael MauboussinA thoughtful investment process contemplates both probability and payoffs and carefully considers where the consensus - as revealed by a price - may be wrong. Even though there are also some important features that make investing different than, say, a casino or the track, the basic idea is the same: you want the positive expected value on your side
Michael Mauboussin