Important quote from Buffett's interview today with CNBC

CARL (reporter): A lot of people who are watching us Warren, and even people who have just started watching us over the past week or two, look at the stock market every day and are confused. They want to use it as a metric for how we're doing, or at least the progress we're making on big issues. I'm guessing you don't think it's reflective of anything that's based in reality right now?

BUFFETT: Well, the stock market in the short -- my old boss Ben Graham said that in the short-run the stock market is a voting machine, in the long-run it's a weighing machine. As a voting machine, it responds to people's emotions. There's no literacy test for voting. You vote according to how much money you have, not according to how smart you (are.) So the stock market does some very silly things in the short-run. Over the long-run, it behaves quite rationally. And, you know, five years from now, ten years from now, we'll look back on this period and we'll see that you could have made some extraordinary buys. That doesn't mean it won't get more extraordinary a week or a month from now. I have no idea what the stock market is going to do next month or six months from now. I do know that the American economy, over a period of time, will do very well, and people who own a piece of it will do well. But they shouldn't own it on leverage. That's what people have learned in this period, that you've got to be able to play out your hand and it's a big mistake to let somebody else be in a position where they can sell you out.