To date, open science has largely depended on bottom-up forces to drive adoption as funders, publishers and governments have often been reluctant to enforce open science norms (Open Research Data Task Force, 2017; Royal Society, 2012). Our analysis reinforces the point that researchers’ sharing behavior is primarily motivated by rational self-interest rather than pure altruism (Fecher et al., 2015; Levin et al., 2016; Haeussler, 2011). Widespread uptake in competitive research environments requires that open science is not only theoretically attractive but that it is beneficial to stakeholder communities. Our analysis revealed key concerns arising from uncertainty about what open science will require of researchers, and the risks open science may pose for professional competitiveness and for relationships with important research partners. To realize the promise of open science for discovery, innovation, research impact and reproducibility, an open science policy must clearly lay out expectations, boundaries and mechanisms for participation, and must be shaped to explicitly support researchers’ values and those of other key stakeholders.