Diameter Pay raises $10 million Series A for stablecoin payments infrastructure

Sep 3, 2026

Diameter Pay, a stablecoin payments infrastructure startup, has raised $10 million in a Series A funding round co-led by CMT Digital and Lightspeed Faction. Originally founded at MIT as SendFriend, the company rebranded in 2023 to offer embedded payment APIs and U.S. dollar virtual accounts. Diameter Pay has processed over $10 billion in payment volume in 2026 year-to-date, partnering with sponsor banks like Portage Bank and SSB Bank to expand dollar access amid tightening global compliance.

Series A funding round

▪As part of the Series A financing, CMT Digital received a seat on the board of Diameter Pay, while Lightspeed Faction and SixThirty Ventures received observer seats.
▪The Series A funding round for Diameter Pay closed as an equity round in a single tranche in July 2026, after beginning in April 2026.
▪Diameter Pay raised $10 million in a Series A funding round co-led by CMT Digital and Lightspeed Faction to expand its stablecoin payments infrastructure.
▪Investors participating in Diameter Pay's Series A round alongside the co-leads included SixThirty Ventures, Stellar Development Foundation, Tech Council Ventures, Onigiri Capital, and BitRock Capital.

Stablecoin payments infrastructure platform

▪Diameter Pay provides payment infrastructure that offers access to U.S. dollar virtual accounts, domestic and international payment rails, stablecoin on- and off-ramps, and compliance controls.
▪Diameter Pay partnered with Flagright to implement real-time transaction monitoring and anti-money laundering screening, with the partnership scheduled to go live in July 2025.
▪Diameter Pay, which was founded in 2017 under the name SendFriend as an MIT college project, rebranded to its current name in April 2023.

Global dollar access challenges

▪Diameter Pay focuses its cross-border payment solutions on emerging Asia to address high transaction costs and financial inclusion gaps.
▪Diameter Pay stated that access to U.S. dollars has become more difficult globally because correspondent banks have withdrawn from certain regions due to rising sanctions and anti-money laundering risks.

Banking partnerships

▪Diameter Pay's sponsor banking partners include Portage Bank, SSB Bank, and an undisclosed publicly traded sponsor bank.
▪Sponsor banks partner with Diameter Pay to gain fee revenue and low-cost deposits in exchange for providing access to U.S. dollar clearing infrastructure.

Regulatory status

▪Diameter Pay is registered as a money services business and as a money transmitter in New Jersey.
▪Diameter Pay employs a team of 20 people across the United States, Argentina, Poland, and Nigeria, and has more than 10,000 live end users.

Company growth metrics

▪Diameter Pay has processed more than $10 billion in payment volume in 2026 year-to-date.
▪Diameter Pay employs a team of 20 people across the United States, Argentina, Poland, and Nigeria, and has more than 10,000 live end users.