Wal-Mart Drama Hits Mexico ETF

Designed to provide broad exposure to the Mexican stock market, EWW lists recognizable companies including Carlos Slim's, America Movil(AMX) , Fomento Económico Mexicano(FMX) , Cemex(CX) and the now-infamous Wal-Mart de Mexico(WMMVY) as some of its largest holdings. The fund is top-heavy too: Wal-Mart de Mexico, alone, represents over 10% of its total portfolio. America Movil, meanwhile, accounts for over one-fifth of EWW's assets.

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As the saga unfolds, conservative-minded investors will likely be best off watching EWW from the sidelines. This event is concerning, but it also stands as an important learning experience. EWW shows how important it is to do the proper homework before diving into a product.