Higher stamp duty for PR and non-residents

Hi Mr. Tan
I understand that more then 30% of buyer in our property are foreigner.
I not against foreigner from buy our property, but I against foreigner HOT money from speculating in  property and hence drive up property price.
Since we have a seller stamp duty, why can the GOV impose a higher stamp duty to curb foreigner from flipping our property. Just addition 5% on-top of the currently stamp duty I think would stamp out most of these unwanted short term activity.
I hope the GOV would consider benefit of its citizens first. Do not forget the people who entrust them with this power in the first place.
Low