Abstract
This study examines how social capital dimensions (structural, relational, and cognitive) shape knowledge sharing between regulators and FinTech innovators within Nigeria's regulatory sandbox ecosystem. It also explores how regulatory trust moderates these relationships, addressing gaps in understanding experimental governance as a tool for technological forecasting and adaptive policy design in institutionally fragile contexts. Guided by Social Capital Theory and Institutional Trust, the study develops a framework linking regulator–innovator interactions to innovation outcomes via knowledge sharing. Data from 345 Nigerian FinTech professionals were analyzed using covariance-based structural equation modelling (CB-SEM). Results show relational and cognitive social capital significantly foster knowledge sharing, which drives regulatory fit adaptation and firm legitimacy, crucial for shaping a stable FinTech future and enabling social change. Structural social capital had no significant influence. Regulatory trust selectively strengthens the link between cognitive social capital and knowledge sharing, highlighting its role in facilitating collective foresight and adaptive regulatory capacity. Policymakers should prioritize building trust-based relationships and fostering cognitive alignment to enhance sandbox effectiveness in developing economies. Such relational investments transform sandboxes into platforms for legitimacy, mutual learning, and adaptive regulatory capacity for future challenges. This research advances understanding of sandbox governance beyond advanced markets, offering a validated measurement approach for future technological forecasting investigations.