Learn how Warren Buffett's "circle of competence" rule for evaluating investments can help you avoid costly mistakes.

Berkshire Hathaway has the cash for Warren Buffett to do one last big deal. And Stephen Wright sees a target that he thinks makes a lot of sense. The post Could this be Warren Buffett’s last big investment?

Tyler Warren still appreciates the blue-and-white team colors. Everything else has changed — his number, the shade of blue he wears, even his new decals-laden helmet. This is what happens when the best tight end in college football turns pro.