If one looks at the annual performance of FXI (China index) versus EWH (HK index), we see a widening spread over the last year, but a lot of simularity in the chart patterns. I suspect these markets are cointegrated, but with a scaling factor (a difference in slope).
This article indicates that chinese will soon be able to invest in the HK market. With the huge flow of speculative money in China soon to be able to find alternative venues (such as HK), should expect to see a move of some of this buying pressure into the HK market.
A speculative play: looking to see a contracting FXI – EWH spread. Trade: buy EHW, sell FXI.