It's buzzing in the Chinese community this morning, and given the size of the price bubble, it may even precipitate a drop in prices as the crazy optimism turns to crazy pessimism.

Has anyone heard any facts about this rumoured tax?

Could be true. I think the Chinese Government can introduce laws that effect the sale or value of property overnight only to let that law go a few weeks later.

This could be just before an auspicious date for buying a house to force a lot of sales now.

June 6th could be auspicious for example.

They're doing the same with weddings too. They've put a limit on the number of weddings that can happen on auspicious days, this encourages people to book their wedding for that day.

Chinese marketing.

maybe ,but just a method to tax the real estate investors

^ I agree with you, but many real estate agents are now helping buyers/sellers bypass that by organising cash deals. I know a guy who did exactly this to avoid tax. This is why the average price per square metre of Shanghai property is lower than it really is. When you think about it, there is no logical reason why the Shanghai property market shouldn't burst and get everybody soaking wet. But the CCP is all powerful.