The annual Value Investor Conference is one of the premier events surrounding Berkshire Hathaway's (NYSE:BRK-B) annual meeting in Omaha. The Motley Fool's Joe Magyer, Michael Olsen, and Rex Moore were in attendance and talked to several value investors. In today's video, Michael chats with Bob Robotti, founder of Robotti & Co., about the differences between investing in Warren Buffett's company and an index fund.