Mastercard: Fifty Years, No Price WarWide moat

Mastercard operates the same two-sided network, charges the same kinds of fee, sells to the same population of financial institutions and competes for the same card portfolios. It is roughly half Visa's size by payments volume and has grown slightly faster in recent years.

In half a century the two have never competed by lowering the merchant discount, and the reason is structural rather than collusive. The network keeps a small share of that fee and the cardholder never sees it, so a cut would forfeit revenue and win no volume whatsoever. Competition happens entirely on the incentive line — bidding for issuer portfolios, $15,751 million of it in fiscal 2025¹ — which is why that line has grown faster than revenue for a decade and why it is the number this app treats as the real competitive scoreboard.

The duopoly is also, awkwardly for the antitrust argument, part of Visa's defence. A single network would have been broken up or regulated as a utility long ago; two large networks look like a market, and each can point at the other when asked why merchants have no alternative. Both have a genuine interest in the other's continued existence.

What would change the analysis is a bidding war that stops being rational — two parties with deep balance sheets competing for a shrinking pool of very large portfolios can pay more than the volume is worth for a surprisingly long time.