This paper examines the paradoxical (post-)growth trajectory of Bitcoin, the first ‘cryptocurrency’, as a case of infrastructural change in digital finance. Bitcoin's founding phase revolved around the principles of self-governance and self-limitation, which combined to create a commitment to degrowing the financial system and limiting monetary production to impede accumulation. Yet growth logics soon began to unfold after Bitcoin's creation in 2009. How and why did that shift occur, and with what implications? We rely on white papers and outputs of alt-coin founders to trace the socio-technical relations underpinning the emergence and expansion of ‘alt-infrastructures’ oriented around growth. We demonstrate how what was originally designed as a post-growth infrastructure largely, albeit not fully, succumbed to conventional growth dynamics over a fairly short period.