Shanghai's second-hand property market has cooled, following the increase of minimum down payment requirements for second-home buyers, with many potential buyers changing their minds at the last minute.

Almost 80 percent of real estate agencies said no contracts were signed on Friday, when the new policy was announced. Agents say most customers -- who had already paid their deposits -- broke their contracts, concerned that more and stricter policies were in the works, like increased taxes.

Analysts believe that 30 percent of buyers will be impacted by the new policy, and that property demand will drop in the near future.