Anti-trust/monopoly doesn't actually hinge on a magical percentage number. The quote from the DOJ: > “We allege that Visa has unlawfully amassed the power to

Anti-trust/monopoly doesn't actually hinge on a magical percentage number. The quote from the DOJ: > “We allege that Visa has unlawfully amassed the power to extract fees that far exceed what it could charge in a competitive market,” This is the thing that's illegal, not some forbidden percentage of market share. Illegally using your position in the market to distort it to your advantage, to prevent competitors from existing, and (generally) to raise prices. From the actual legal complaint https://www.documentcloud.org/documents/25173584-visa-lawsuit-doj https://www.documentcloud.org/documents/25173584-visa-lawsui... > Visa is a monopolist in the general purpose debit network services and general purpose card-not-present debit network services markets in the United States with market shares of at least 60% and 65%, respectively, by payment volume. Mastercard is the second largest debit network in the United States and processes less than 25% of debit transactions in either relevant market. No other competitor has more than a single digit share of debit transactions in either market. > Visa has monopoly power in the relevant debit markets because it has the power to control prices and exclude competition in each market. Of course, the whole court case will be arguing whether Visa has the power to control prices and exclude competition. DOJ thinks they do, I'm guessing Visa thinks they're fine!