In a similar way that the behaviour in US markets overnight...

In a similar way that the behaviour in US markets overnight gives ASX investors/traders a feel for the day ahead, you will find that Melco Crown overnight movement works as a loose predictor for movement in CWN. Only there are stronger reasons for the latter of these correlations: CWN's stake in Macau.

In this case, unflattering analysis following more bad news from Macau resulted in a drop in Melco Crown overnight (from memory, 4ish percent). Given the proportion of CWN's value attributable to Macau, it's quite reasonable to expect this to result in a 2ish percent drop in CWN.

EDIT: I can only guess the remaining 2ish percent drop in CWN to be a mild over reaction.