In addition to laying the groundwork for value investing, Ben Graham gave us a vivid metaphor that has been recycled and re-imagined by value investors including Warren Buffett and Seth Klarman ever since: Mr. Market. In his latest white paper Michael Mauboussin, managing director and head of Global Financial Strategies at Credit Suisse, finds that Mr. Market is still a useful way to think about markets, but his extreme mood swings don’t happen at random, they’re caused by a lack of diversity. Value investors have to agree with both Shiller and Fama, says Mauboussin “To be an active investor, you…