...but if US investors can buy on the Canadian exchange through a regular brokerage account for a modest fee then what's the problem? There is no market in Tyhee shares in the UK but I can trade the shares by doing exactly that through TDW. I keep all my spare cash in C$ because I only trade in shares on the Canadian exchanges so it's a one off exchange loss (which will be built into the brokers' margins when trading on the pinks anyway).

I really don't see the point of the pink sheets other than an opportunity for US brokers to make money out of investors and potentially manipulate the stock of small and thinly traded companies. Surely trading would be more transparent and liquid if it was all done on the TSXV?