Behavioral biases are very important to be properly understood by portfolio managers, analysts, traders and all types of investors. In fact, almost everyone who looks at the 'market as a guide' tend to be influenced by their emotions rather than by logic. Apart from overconfidence and consensus comfort, there are various other biases such as loss aversion, falling to a nice story (what most sell-side analysts or marketing pitches do in their reports) which are very nicely written by James Mortimer in his book " The little book of behavioural investing" which I found it to be fantastic.