Social currencies can make a valuable contribution to sustainability as they strengthen solidarity markets, a specific exchange practice that enhances the resilience of their surrounding environmental, social and human systems. Until now, the need to secure trust in a currency has been a major challenge for social currency initiatives not backed by the State. The emergence of Blockchain, which offers security, transparency and auditability to currencies and transactions it supports, seemingly circumvents this issue. This raises the question that this paper seeks to address: is Blockchain a game-changer for bottom-up solidarity economy initiatives? The methodological approach draws on a multidimensional conceptualization of trust that recognizes three components: ethical, hierarchical and methodical trust. It uses Moneda PAR, an Argentinian Blockchain-based social currency, as a case study and draws on use data, participant surveys and direct observation by the authors as action researchers to explore social currency and solidarity economy development in relation to currency performance on each dimension of trust. Findings from the case show that despite strengthening hierarchical and methodical trust, Blockchain needs to be articulated with additional market-building strategies to be a true game-changer in the development of social currency systems.