[CanadianCapitalist]

You can use actual exchange rates in effect on the dates of transaction, or annual average exchange rates, whichever is more advantageous to you ... but you have to pick a method an stick with it ... no cherry picking allowed.

I think the first post has an error as well. I used to be with Questrade and their US stock commissions are in US dollars, just like everybody else.

I agree with Cardhu's post. You can use actual exchange rates on the date of transaction or the annual average exchange rates.