The Justice Department filed an antitrust lawsuit on Thursday, alleging that Visa's proposed acquisition of Plaid would limit competition.
In a statement, the DOJ said, "Visa seeks to buy Plaid — as its CEO said — as an 'insurance policy' to neutralize a 'threat to our important US debit business.'" The argument seems to be that Plaid, which helps connect financial companies to each other, would help Visa maintain a monopoly in online debit transactions.
The suit could halt the $5.3 billion acquisition, which was set to be one of the biggest fintech deals yet. In a statement, Visa said the the DOJ's attempt is "legally flawed and contradicted by the facts."