Joining John Paulson in support of corporate raider Carl Icahn's plot to force a Microsoft-Yahoo merger, Texas oilman and longtime Icahn ally T. Boone Pickens purchased 10 million shares of Yahoo. Pickens told CNBC he plans to support Icahn in a proxy fight. By our count, PIckens's addition puts 30 percent of Yahoo shares in control of those favoring a merger with Microsoft — a merger that Microsoft, having been rebuffed the last time, has yet to propose.

Paulson is the founder and president of Paulson & Co., a hedge fund with more than $12 billion under management. He's best known for predicting the global credit crisis, which earned him a staggering $3.3 billion in 2007.