A real estate bubble, probably.Does a real estate bubble popping impact the US much? Maybe some, but not nearly as much as most think it would. China's built a new middle class through exporting goods to much of the rest of the world. Personally I don't think a real estate bubble is going to cut off demand for China's exports, but the news headlines when it does happen will scare the crap out of ill informed market players (retail types). Japan did this back in the 90's, but through much of the last 20 years Japan has been in a deflationary state despite their hay day of exporting and QE. QE has done little to help Japan inflate and it's also done little to help the US inflate. Reason being is that QE isn't easy money, it's actually an extraction of money from the private sector (deflationary). If you take a USD chart and plot out QE you'll see dollar values have risen each time. Supply and demand, QE is removing supply as demand increases and continues to increase. The up's and downs are other central banks adjusting in an attempt to make their exports cheaper/more attractive. Right now China is providing the least expensive exports, hence the outside demand for their goods, boosting employment and the middle class there. If and when it gets to the point that China wants to consume it's goods locally rather than export them, someone else will take their spot, just like they took Japans spot in global trade.