Stablecoin payment volume has reached an estimated $390 billion a year, with B2B transactions up roughly 733% year over year, according to McKinsey and Artemis. Visa’s stablecoin settlement volume hit a $7 billion annualized run rate by April 2026, up 50% in a single quarter. For business owners operating across borders, that shift could ease a familiar headache: juggling multiple providers, currencies and layers of fees just to move money internationally.
In March, Mastercard announced that it would acquire stablecoin infrastructure startup BVNK for up to $1.8 billion. “When the legacy rails start building on the new rails rather than competing with them, the demand debate is over,” Alex Witt, general partner at Verda Ventures, told me in written responses.
Amid that shift, the California-based fintech Flex, sometimes described as “Brex for business owners”, has raised $70 million in a Series B1, led by Halo Fund, to build on that premise. Flex Global, its stablecoin-powered cross-border banking platform, offers multi-currency accounts in 32 currencies across 170 countries.
The Middle Market Nobody Banked
“About 350,000 business owners in the U.S. manage 40% of American payroll,” Flex founder and CEO Zaid Rahman said to me in an interview. “About three million business owners manage 50% of the global economy.” Rahman’s thesis is that the ends of the business spectrum are well served — micro-businesses by Square and Toast, large enterprises by Ramp and its peers — while the middle has largely been left open. Many of these owners operate across multiple entities, currencies and jurisdictions, making cross-border money movement part of their day-to-day operations.
Flex’s core customers generate between $3 million and $200 million in annual revenue, primarily in construction, wholesale and import-export, yet many run their back office across twenty-odd tools, and more than half send over $1 million in international wires every month. The answer is a single dashboard for an owner operating in Dallas, Mexico City, Dubai and Warsaw at once.
Stablecoins Move Behind The Scenes
Stablecoins are becoming a backend technology — something the customer never sees, buried under an interface that looks like ordinary banking. “We don’t really care about any one payment rail,” Rahman said. “Stablecoins are just another payment rail for us. What we care about is user experiences for customers to do business faster, cheaper, better.” His example is a wholesale electronics exporter shipping $20 million of goods to Latin America every week.
Executing that foreign exchange in real time was historically cumbersome. “Now with stablecoins, you could do that instantly and lock in a moment-in-time price,” he said — a feature that matters to the business owner far more than the technology underneath it.
Traditional cross-border payments take one to five business days and cost 1% to 6% all-in. Stablecoin rails settle in minutes, around the clock, at a fraction of a percent. Flex’s volume running on stablecoin rails already exceeds $1 billion annually, according to Rahman, a fast-growing share of Flex’s $10 billion in annualized payment volume.
The Stablecoin Moment
The GENIUS Act, signed a year ago, created a federal framework for payment stablecoin issuers in the U.S., while the European Union’s stablecoin provisions under MiCA are now in force. “Two years ago, orchestrating customers across SWIFT, wires, RTP and real-time stablecoin settlement within a single platform was simply difficult,” Rahman said.
This is not the first time a fintech is making stablecoins invisible behind a familiar interface. In 2025, Stripe completed its $1.1 billion acquisition of the infrastructure firm Bridge and has since used its technology to launch stablecoin accounts in 101 countries. PayPal expanded PYUSD to 70 markets.
Faster settlement, however, does not eliminate every layer. Julia Demidova, head of digital currencies and strategy at the banking technology group FIS, said the transfer itself is the easy part.
“Most businesses do not only need a token transfer,” she said. “They need FX, reconciliation, sanctions screening, transaction monitoring, wallet controls, accounting treatment, refund and exception handling, reporting and integration into bank systems. The transfer may settle quickly, but the end-to-end operating model remains complex.”
Stablecoins do collapse some correspondent-banking hops, she said. “But they do not remove intermediation altogether. They relocate it.” Once a payment touches local currency, sanctions screening or custody, a new cast enters the chain: issuers, custodians, liquidity providers, FX desks, off-ramp partners and local banks.
A Different Bet On The Future Of Banking
Large banks have pursued tokenized deposits instead — commercial-bank liabilities on a blockchain, such as JPMorgan’s Kinexys — rather than public stablecoins issued by non-banks like Circle and Tether. Rahman expects the technology to win regardless. “The technology is never going to go away,” he said. “In fact, every bank, from JPMorgan to American Express, is adopting it.” Michel Jacobs, chief strategy officer at CSI, which builds core banking software, argues the sharper advantage is not speed but programmability: a stablecoin payment can carry its own logic — funds released when a shipment is confirmed, escrow held until a milestone is
met, royalties distributed automatically, which ACH and wire rails cannot do. In his view, that ultimately favors banks rather than challengers, since the institutions with a deposit anchor can build relationships a fintech cannot replicate.
Revolut, the London-based digital bank, already offers zero-fee stablecoin conversion and stablecoin payments in some markets. Rahman argues the rails are beside the point.
“Fintech in itself is a commodity,” he said. “Every single payment rail is commoditized, including stablecoins, including ACH, including wires. A card payment is a card payment. All of that does not matter to us.” What matters, he argues, is rebundling — consolidating business banking, personal finance, payments, credit and back office into what he calls “the full financial home for ambitious business owners.”
The sharper differentiator is credit. Flex’s most popular U.S. product is a net-60 card giving owners 60 days of interest-free float, aimed at businesses like construction firms whose clients pay late. Underwriting the middle market is slow work — banks average 90 days, and Flex itself took 40 to 50, but using AI to read financials, bank accounts, ERP systems and vertical tools like Procore, the company now turns credit decisions around in two days.