This study investigates family social capital “stock and flow” processes defined by social capital access and use at the family‐firm nexus over time. We examined direction of effects in associations between family functional strength and business‐related tension moderated by firm continuation status using National Family Business Panel data, grounded in the Sustainable Family Business Theory (SFBT). Families continuing ownership experienced greater family functional continuity, which was associated with less business‐related tension over time. Families discontinuing ownership exhibited less functional continuity with a family and business disengagement pattern. Regarding bridging of family capital resources, differences were found in human, social, and financial capital that were associated with family functional strength and business‐related tension for each ownership group. For both groups, however, making family a priority over firm was associated with stronger family functionality. Contributions include theoretical and methodological distinctions between family capital stocks and flows and support for SFBT theoretical propositions.