Billionaire hedge fund executive Steven Cohen is dipping his toe even further into the reinsurance market with the purchase of a 5.2 percent stake in Bermuda-based Validus Re.This, according to a brief in BusinessWeek. The news comes on the heels of the announcement that Cohen’s company, SAC Capital Advisors, is looking to open SAC Re in Bermuda early in 2012. Former Lancashire Holdings' boss, Simon Burton, was chosen to head up the new reinsurer.According to Reuters, SAC Re will concentrate on property and casualty coverage.Mr Cohen is one of a handful of hedge fund billionaires entering the reinsurance market, following behind David Einhorn of Greenlight Capital and Daniel Loeb of Third Point.“I call it the sheep theory,” said industry consultant Andrew Barile to Reuters in October when plans for SAC Re were originally announced. “When one sheep leaves the barn they all follow and it is exactly the same with the hedge funds. When one successful manager makes the decision to go into reinsurance, the others follow.”“We haven't had a lot of new reinsurers launched in the last five years, but that is clearly changing,” he added.SAC Capital Advisors controls $14 billion in assets and in September, Forbes estimated Cohen’s net worth to be $8.3 billion.