The Most Important Thing Illuminated: Uncommon Sense for the Thoughtful Investor (Columbia Business School Publishing)

by Howard Marks

Economies and markets cycle up and down. Whichever direction they’re going at the moment, most people come to believe that they’ll go that way forever. This thinking is a source of great danger since it poisons the markets, sends valuations to extremes, and ignites bubbles and panics that most investors find hard to resist.

being part of the herd is a formula for disaster,

When other investors are unworried, we should be cautious; when investors are panicked, we should turn aggressive.