The Department of Justice (DOJ) filed an antitrust lawsuit against Visa. The lawsuit alleges that the financial firm holds a monopoly over debit network markets allowing it to charge banks and markets with exorbitant fees that get passed onto consumers and keep rival companies like PayPal and Square from competing on their level.

Visa shares fell 3% on Tuesday after a report said the U.S. Department of Justice plans to file a lawsuit against the world's largest payment processor, alleging it illegally monopolized the country's debit-card market.