"The idea that you try to time purchases based on what you think business is going to do in the next year or two, I think that's the greatest mistake that investors make because it's always uncertain. People say it's a time of uncertainty. It was uncertain on September 10th, 2001, people just didn't know it. It's uncertain every single day. So take uncertainty as part of being involved in investment at all. But uncertainty can be your friend. I mean, when people are scared, they pay less for things. We try to price. We don't try to time at all."

Source: Warren Buffett's 'Stock Split' Interview. Squawk Box with Becky Quick, www.cnbc.com. January 10, 2010.