Warren Buffett: What others are doing mean nothing

“Ben Graham said long ago that you’re neither right nor wrong because people agree with you or disagree with you. In other words, being contrarian has no special virtue over being a trend follower. You’re right because your facts and reasoning are right. So all you do is you try to make sure that the facts you have are correct…. And then once you have the facts, you’ve got to think through what they mean. And you don’t take a public opinion survey. You don’t pay attention to things that are unimportant. What you’re looking for [are] things that are important and knowable. If something’s important but unknowable, forget it. I mean, it may be important to know whether somebody’s going to drop a nuclear weapon tomorrow but it’s unknowable. And there are all kinds of things are that knowable but are unimportant. In focusing on business and investment decisions, you try to narrow it down to the things that are knowable and important, and then you decide whether you have information of sufficient value that—compared to price and all that—will cause you to act. What others are doing means nothing.”

—Warren Buffet.