Acquired by Greater Sum Ventures in 2020, Stax is a leading provider of business management software solutions and omnichannel payment capabilities to SaaS platforms and the SMB marketplace. Originally launched in 2014 as Fattmerchant, Stax has broadened its offering to include integrated APIs, subscription billing, and white-labeled PayFac capabilities—designed not only for merchants, but also ISVs and platforms looking to embed payments natively into their software.

As the business grew and the platform matured, Stax made strategic acquisitions to deepen its technology stack and expand its go-to-market reach. In 2024, it acquired BlockChyp, a modern gateway and point-of-sale provider, bringing gateway-level control and real-time encryption into its ecosystem. It also acquired APPS, a payment technology provider, to serve as the foundational processing layer powering fintech offerings for ISVs, ISOs, and SMBs

Today, Stax serves over 39,000 businesses and software platforms across North America and processes over $23 billion in payments annually. Its infrastructure powers billing, payments, subscriptions, and customer engagement for some of the most innovative SMBs in the U.S. market—helping business owners focus on growth and not the complexity of financial infrastructure.

Recapitalizations

• February 2022, PSG