I've never looked into it, but I've wondered how closely correlated US shares of a Canadian company trade to the Canadian shares.
I wonder if there are any opportunities to somehow play an arbitrage. Lets say there's a Canadian stock, trades on both Toronto Stock Exchange and US:OTC
Maybe the US shares move less percentage-wise up or down, compared to the Canadian shares.
Go long the Canadian shares, and short the US shares of a company or vice versa lol.
Even if it worked, every few days (or every day) you'd have to re-balance the funds of each side. Too much work