Quote from KeithOmalley:
so i could just trade US stocks that trade on other exchanges?
If this did happen which I only see a small chance it would this would be a good solution. Most likely we would also see these foreign exchanges open up for longer hours to match the us time zones.
China also just removed their stamp tax will now allow margin and also will allow shorting. So there will always be Shanghai. Or you could always move up here to Canada, but we would copy you because our parliment has never seen a tax scheme they did not like.

