Diameter Pay Raises $10 Million to Expand Stablecoin Payments Infrastructure

Diameter Pay has closed a $10 million Series A to grow the plumbing behind stablecoin payments, foreign exchange, and cross-border dollar movement. For high-risk PSPs, the interesting part is not the headline number; it is that the company is selling access to U.S. dollar virtual accounts, payment rails, and compliance controls through U.S. banking partners.

1. The round was co-led by CMT Digital and Lightspeed Faction, with participation from SixThirty Ventures, Stellar Development Foundation, Tech Council Ventures, Onigiri Capital and BitRock Capital, according to a Thursday report in The Block. Diameter Pay said this was its first outside funding round, and founder and CEO David Lighton said the company was bootstrapped before the Series A.
2. The equity round began in April and closed in July in a single tranche. Lighton declined to disclose the post-money valuation, so there is no pricing signal here beyond the fact that the company got the deal done and did not dribble it out over multiple closes.
3. Founded in 2023, Diameter Pay provides payment infrastructure to banks, FinTech companies and digital asset exchanges. Its platform offers U.S. dollar virtual accounts, domestic and international payment rails, stablecoin on- and off-ramps, and compliance controls through U.S. banking partners, according to The Block.
4. Lighton said the virtual accounts let foreign FinTech companies offer U.S. dollar accounts to their customers while Diameter Pay manages compliance and payment controls. The accounts can also connect to stablecoin infrastructure, which makes the product relevant to operators trying to move between fiat and digital assets without building the whole stack themselves.
5. Diameter Pay said it began processing payments for foreign banks in 2024 and has processed more than $10 billion in payment volume this year. Its sponsor banking partners include Portage Bank and SSB Bank, plus a third publicly traded sponsor bank that has not been disclosed, and Lighton said additional banks are being onboarded.

Diameter Pay said access to dollars has become more difficult in some markets as correspondent banks have withdrawn from certain regions amid increased sanctions and anti-money-laundering risks. That is the core commercial angle for the high-risk crowd: if a provider can keep U.S. dollar access and compliance controls working in that environment, it becomes more than a payments vendor; it becomes part of market entry.