Visa (V) shares slumped lower Friday after the Wall Street Journal reported that the U.S. Department of Justice is investigating the group's debit card business.
The Journal said the DoJ's antitrust division is looking into allegations that Visa limited the ability of merchants to route debit card transactions in order to limit so-called 'network fees'. Visa, which operates the largest card network, was thwarted by the DoJ earlier this year in its attempt to purchase fintech start-up Plaid for $5.3 billion.
The DoJ had argued that is "a monopolist in online debit, charging consumers and merchants billions of dollars in fees each year to process online payments". Assistant Attorney General Makan Delrahim called the merger collapse "a victory for American consumers and small businesses."
"American consumers and business owners rely on the internet to buy and sell goods and services, and Visa - which has immense power in online debit in the United States- has extracted billions of dollars from those transactions," he added.
Visa shares were marked 5% lower in late-morning trading Friday to change hands at $209.75 each following the Journal's report, trimming their six-month gain to around 6.25%. The shares have a market value of around $450 billion.
Visa topped revenue and earnings estimates for its fiscal first quarter, which ended in December, helped in part by improvements in payments volumes, which rose 5% over the prior year on a constant-dollar basis, the company said. Total processed transactions rose 4% to 39.2 billion for the quarter from the same period a year ago, Visa said.