Technical question here to people who have more experience with international investing. Why is there such a large difference between the OTC shares of Volvo and the Swedish Nasdaq listed ones? e.g. Per the graph on the bottom: The lines over the shared area below are VOLV A and VOLV B - which track almost identically on top of each other - expected. The 2 free lines (orange/yellow) are VOLVF and VLVLY, which aren't identical, but since these trade in low volume it's not unexpected - and they're still close to each other. But why the large difference between the Swedish Nasdaq issue and American OTC issues? Any arbitrage computer should have had a field day with this. Are there large conversion costs or taxes involved that causes them to drift by that much?