You are probably better off with AMX. AMOV has a lot less liquidity, which can sometimes be a good or bad thing. I've seen AMOV trade at premiums and discounts of up to 10% intra-day compared to AMX, but they are the same stock. They should be valued the same. I think the only difference between them is that AMOV may have voting rights in the company, but this benefit is kinda moot since Carlos Slim and his family own a majority of the voting shares so they control the company.