Diameter Pay has raised $10 million in a Series A financing round co-led by CMT Digital and Lightspeed Faction, as the company reported processing more than $10 billion in payment volume year-to-date in 2026. The funding was announced on September 3 and is intended to support the company’s expansion of infrastructure for cross-border access to U.S. dollars.
The reported volume is a company disclosure rather than an independently verified figure. It nevertheless provides the clearest scale marker offered alongside the financing for Diameter Pay, which serves financial institutions and digital-asset businesses moving money across domestic and international channels.
Diameter Pay’s $10 million Series A and investor group
Diameter Pay said CMT Digital and Lightspeed Faction co-led the round. SixThirty Ventures, Stellar Development Foundation, Tech Council Ventures, Onigiri Capital and BitRock Capital also participated.
The company did not provide a valuation or disclose the ownership terms of the Series A in its announcement. Its stated payment-volume figure covers the year through the September 3 announcement, rather than a full-year total.
The raise arrives as companies building payment infrastructure seek to combine conventional banking connections with stablecoin settlement and foreign-exchange functionality. Diameter’s stated focus is narrower than a consumer payments offering: it is selling the underlying account, payment and compliance capabilities to institutional customers and platforms.
The API stack connecting dollar accounts, payment rails and stablecoin ramps
Diameter Pay provides banks, fintechs and digital-asset exchanges with U.S. dollar virtual accounts, domestic and international payment rails, stablecoin on- and off-ramps, and embedded compliance controls through a single API, according to The Block.
Virtual accounts can give an institution or its customers account-level payment functionality without requiring every user to build a separate banking integration. In Diameter’s description of the product set, those accounts sit alongside rails for payments within the U.S. and across borders, as well as mechanisms to move between stablecoins and traditional money.
The single-API model is central to the company’s pitch. Rather than separately connecting to account services, payment routes, stablecoin conversion tools and compliance processes, a customer can access those elements through one technical interface. That approach is designed for businesses that need dollar movement and digital-asset access as part of a broader financial product.
Embedded compliance controls are also part of the offering. Diameter has not, in the information released with the funding, specified the individual controls or jurisdictions covered, but their inclusion signals that compliance tooling is being positioned as a core component of cross-border payment infrastructure rather than an add-on.
Funding targets banking, FX and compliance expansion
Diameter said it will use the Series A proceeds to expand its banking and payment capabilities, deepen its stablecoin and foreign-exchange infrastructure, and invest in technology and compliance tools for cross-border dollar movement.
Those priorities map directly to the separate components of the company’s platform. Banking and payment capabilities concern access to dollar accounts and payment rails; stablecoin and FX infrastructure address conversion and cross-border movement; and technology and compliance investments support the operational framework around those services.
The announcement framed the work around expanding global access to the U.S. dollar. It did not set out a timetable for the product expansion, identify additional markets, or provide targets for payment volume or customer growth following the financing.
From foreign-bank payments to users across Switzerland and Singapore
Founder and Chief Executive David Lighton told The Block that Diameter Pay was founded in 2023 and began processing payments for foreign banks in 2024. At the time of the announcement, Lighton said the company had more than 10,000 live end users.
That operating history places the company’s reported volume growth against a relatively short timeline. The available disclosures do not break down the 10,000-plus end users by customer type, country or payment activity, and they do not specify how much of the reported payment volume is connected to stablecoin transactions.
SixThirty Ventures separately confirmed its investment in the Series A on September 4. The investor said the platform’s users span clients from Switzerland to Singapore, offering independent confirmation of the company’s geographic reach across those two markets.
For Diameter, the financing now puts the emphasis on building out the banking, payment, stablecoin, FX and compliance layers it says are needed to support cross-border dollar access.
