During their monthly meetings, Curiel would ask Franco to sign documents in English that Franco could not understand, including an International Swaps and Derivatives Association agreement that facilitated the foreign exchange and option transactions, the complaint alleges.

FORBES: Mexican Investor Blames Citigroup For $50 Million In Personal Losses

For U.S. investors looking to gain exposure to stocks that only trade on foreign markets, one option is to buy an ETF that holds these stocks directly on the foreign exchange.

FORBES: Foreign ETFs That Speak The Language

Foreign securities are another option, but investors can buy them only through a securities firm, and the Foreign Exchange and Foreign Trade Control Act still puts obstacles in their way.

ECONOMIST: Not all it should be