Circle Internet Group Inc. and Stripe Inc. are racing to build payments systems for a world that doesn't exist yet — one where autonomous AI agents transact millions of times a day, settling in stablecoins instead of swiping credit cards. Two weeks ago, a Citrini Research scenario imagining AI agents routing around card network fees sent Visa Inc., Mastercard Inc. and American Express Co. shares tumbling as much as 5% in a single session.

Instead, the idea migrated from a speculative Substack post into earnings calls, and accelerated enthusiasm around product launches and blockchain buildouts. On its Feb. 25 earnings call, Circle CEO Jeremy Allaire argued that stablecoins could become the native currency of machine-to-machine commerce. The stablecoin industry is now positioning agentic payments, high-frequency, low-value transactions between software agents, as a use case to justify the entire infrastructure buildout.

Investors have piled into both companies, though not solely for the agentic vision. Circle shares surged after a blowout earnings report, and Stripe recently notched a $159 billion valuation driven by $1.9 trillion in payment volume. The agentic bet is layered on top of businesses already growing without it. The gap between ambition and adoption remains stark.