PhotonPay has closed a $40 million Series C round led by Blockchain Capital to expand its stablecoin-focused Financial OS. SBI Group joined as a new investor, alongside existing backers IDG Capital, GL Ventures and Lightspeed Faction. The funding follows a January 2026 Series B round. PhotonPay reported $65 billion in annualized transaction volume as of August 2026, up from $30 billion reported at the time of its Series B. Its model combines stablecoin liquidity with bank relationships and local payment networks, rather than replacing those networks outright. The company says it holds 34 payment and financial licenses and regulatory authorizations and serves more than 200,000 corporate clients. It also plans an execution layer supporting the Model Context Protocol for autonomous AI agents. The expansion comes as Stripe and specialist firms including Rain and MassPay pursue corporate settlement opportunities.