Diameter Pay Raises $10M for Global Dollar Infrastructure

Correspondent banking retreat has turned access to the U.S. dollar into a product problem. Banks and fintechs can see demand from legitimate customers across emerging markets, digital-asset businesses, and cross-border corridors, yet every new relationship adds sanctions, anti-money-laundering, settlement, and counterparty risk that must be understood before money moves.

Diameter Pay has raised a $10M Series A to build more of the infrastructure inside that decision. The financing was co-led by CMT Digital and Lightspeed Faction, with SixThirty Ventures, Stellar Development Foundation, Tech Council Ventures, Onigiri Capital, and BitRock Capital participating.

The company announced the round on September 3, 2026 and said the capital will expand its banking and payment capabilities, deepen its stablecoin and foreign-exchange infrastructure, and strengthen the technology and compliance tools required for cross-border dollar movement. Diameter Pay reports processing more than $10B in payment volume year-to-date in 2026, giving the round an operating record to scale rather than only a market thesis to test.

The broader significance sits between two financial systems. Stablecoins can make dollar value programmable and available around the clock. Regulated banks still control access to accounts, clearing, compliance, and settlement. Diameter Pay is trying to make that institutional seam into a platform.

What Diameter Pay Announced

The $10M Series A is Diameter Pay's first financing round, according to the company and founder and CEO David Lighton. The Block reported that the equity financing was completed in one tranche after fundraising began in April and closed in July. The company did not disclose its valuation.

CMT Digital and Lightspeed Faction co-led the round. SixThirty Ventures, Stellar Development Foundation, Tech Council Ventures, Onigiri Capital, and BitRock Capital joined the syndicate. CMT Digital received a board seat, while Lightspeed Faction and SixThirty received observer seats, according to Lighton's interview with The Block.

Those governance roles matter because the financing is entering a regulated operating environment. Diameter Pay is not selling a lightweight software tool that can be separated from the institutions around it. Its product depends on sponsor banks, payment networks, compliance data, licensing, and financial institutions willing to trust the controls around each transaction.

The Product Lives Inside the Risk Decision

Diameter Pay gives banks, fintechs, and digital-asset exchanges access to U.S. dollar virtual accounts, domestic and international payment rails, stablecoin on- and off-ramps, and embedded compliance controls through a single API. Its official website says the company provides embedded payments to banks and financial institutions across multiple payment systems and currencies.

The customer is buying more than movement. A foreign fintech may want to offer U.S. dollar accounts to its own users, but it still needs a regulated path into the banking system and a way to screen counterparties and transactions. Diameter Pay places the account, payment, stablecoin, and compliance layers inside one institutional relationship.

The company reports more than 10,000 live end users. Lighton told The Block that Diameter Pay earns payment fees and sells directly to financial institutions that bring their customers onto the platform. The report identifies Portage Bank and SSB Bank as sponsor banking partners and notes that a third public-company bank remains undisclosed.

Those figures and relationships are company-reported rather than independently audited. Named clients, revenue, and the identity of the third sponsor bank are not public. The useful evidence is still concrete: Diameter Pay says more than $10B moved through the platform during 2026 before it raised this round.

From SendFriend to Diameter Pay

Diameter Pay operates as SendFriend, Inc. DBA Diameter Pay. The company rebranded from SendFriend in April 2023 after moving from a financial-inclusion origin into embedded cross-border payments for institutions.

The company's official about page says it was founded at MIT. Lighton's background helps explain the continuity: Yale's Global Justice Program describes him as a former World Bank staff member who worked on financial inclusion and payment access after the Haiti earthquake. That experience points toward the same problem Diameter Pay now addresses commercially: financial access can disappear when institutions cannot price or manage the risk of serving a market.

The 2023 rebrand announcement also disclosed a $2.9M European Union R&D grant. That support is non-dilutive, so it should be kept separate from the Series A and does not turn the earlier grant into an equity financing round.

What the $10M Changes

Diameter Pay plans to use the capital across banking relationships, payment capabilities, stablecoin and FX infrastructure, technology, and compliance. The Block also reported that the 20-person company is recruiting a CTO and a chief commercial officer, with a core team in the United States and additional teams in Argentina, Poland, and Nigeria.

The hiring plan exposes the dual burden of this category. Diameter Pay has to deepen technical integrations while building the commercial and compliance capacity to support regulated institutions. A faster rail has limited value if onboarding stalls, screening breaks, settlement fails, or a sponsor bank becomes uncomfortable with the risk it is carrying.

The investors are underwriting that combined problem. CMT Digital brings digital-asset infrastructure context. Lightspeed Faction invests across blockchain businesses. SixThirty focuses on regulated fintech and enterprise financial technology. Their presence around the board suggests that scaling the connective layer, rather than choosing between traditional finance and digital assets, is the central bet.

The Market Signal Behind the Round

Stablecoin adoption is often framed as a replacement story. Diameter Pay's model points toward interdependence. Digital dollars can improve availability and settlement options, while banks remain essential for regulated account access, clearing, deposits, and the trust required to serve institutional customers.

That creates a valuable but demanding layer between systems. The companies that own it must translate programmable money into controls a bank, regulator, compliance officer, and customer can all understand. The interface may be an API, but the product is permission supported by evidence.

Diameter Pay's $10M gives the company more room to widen that permission without making the controls thinner. The next record will be written in the institutions it can name, the corridors it can serve, and whether reported payment volume can keep compounding while sponsor banks remain comfortable carrying the other side of the transaction.