Yes, the world's biggest short bet that crude oil prices will fall is Fed Chairman Ben Bernanke. Based upon the Fed's statement yesterday at the close of the FOMC meeting, crude oil and other commodity prices should soon start to moderate, and perhaps fall. The financial markets perceived the statement as being weak on the Fed's commitment to fighting inflation. The statement was perceived similarly by both commodities and stock markets, causing stock market index futures to fall, and inciting a reaction of higher prices across the board in the commodity markets.
If this morning's follow-through of prices in both arenas is any indicator, the Bernanke Fed has made a bad bet. They shorted oil, and prices moved higher, with stocks moving sharply lower in reaction.