I only have cursory knowledge of the Canadian exchanges, more familiar with us exchanges and how "Market Makers" control the OTC. A broker or series of brokers aquire securities, usually penny stocks, than list them on one of the 3 OTC markets. (I don't know which market MGC is listed on, I know it isn't a pink sheet). I don't know if any Canadian exchanges have a true equivalent. I know that the CSE has an alliance with the OTC in issuing of IPO's in order to access the larger us capital market.
That's about all I know and don't really know the semantics of how exchanges interact.
I know Canopy Growth (Canadian)has a, I think 19% stake AUSCANN which is only on the AUS and OTC exchanges. I know of no other Australian companies I've researched being listed in Canada.
Maybe the OTC is a unique "exchange" and offers a one of a kind investing opportunity for US investors.
Sorry if I opened a can of worms here, just thought if there was or is a vehicle to get exposure in the booming Canadian market it would be a bonus.