Hi, pic,
ECUXF will never trade much higher than ECU.TO, since the arbs would take advantage of it. As I've said before, they are the same stock just labeled differently. If you pay more for ECUXF than what the exchange rate says you should, you are being taken advantage of by the pink sheet broker. He is selling you at one price and buying it on the TSE or other pink sheet broker at a lower price.
I don't know how else I can say it. There is not a separate issue of ECU stock trading exclusively in the US. It is TSE stock sold in the US with letters identifying such. Either that or the guys on Schwab's global desk are whacko.