China is going through a property boom. The master of short selling, Jim Chanos, questioned China's real estate investments and said he is now shorting China. Al Jazeera's Melissa Chan reported from Ordos Shi in Inner Mongolia, a town of one million people built with stimulus money that has almost no residents. Shorting China was one of Chanos' favorite investments in 2010. Chanos didn't explain how specifically he shorts China but he hinted at shorting companies and industries that are benefitting from China's real estate bubble. Recently Jim Chanos raised $20 Million for an offshore hedge fund that would probably place short bets against China's property bubble. When economists like Nouriel Roubini make contrarion and pessimistic predictions, we don't really pay any attention. They have no skin in the game. Not many people remember pessimistic predictions that didn't come out true in the past. For example, Roubini's recession predictions in 2004 fell flat even though oil prices surpassed the $40 per barrel mark. Today we would love to buy oil at $40/barrel. Six years ago Roubini thought it is a huge concern for the economy. We don't pay attention to contrarion economists' predictions but we do pay attention to a multi-billion dollar hedge fund's predictions. If Chanos' predictions are wrong, he would lose millions of dollars.  Chanos isn't alone in his pessimistic views about China, either. Other hedge fund managers are starting to short China as well. According to The Telegraph, Hugh Hendry of Eclectica Asset Management has launched a distressed China fund. Corriente Advisors' Mark Hart, who considers China as an enormous tail risk, also launched a China fund. Monaco based hedge fund, Pivot Capital Management, is also shorting China. The Telegraph reports that there is also a Mayfair hedge fund manager who is shorting China. Most investors don't agree with China bears. They don't think China is on an "economic treadmill to hell", as Chanos calls it. Harvard University's Kenneth Rogoff disagrees. Last year, Rogoff predicted that China's growth rate will plunge to as low as 2% after its bubble burst. His prediction isn't as bold as Chanos'. Rogoff's time frame for this prediction is 10 years. Insider Monkey, your source for free insider trading data, hasn't made up its mind. We are waiting for Robert Shiller's comments about China. Shiller is the ultimate authority on bubbles and if he calls China a bubble then it must be a bubble.