This talk will summarise work done within the EC Horizon2020 project ON-MERRIT (2019-2022, https://on-merrit.eu/) to investigate risks of cumulative advantage in the transition to Open Science. Open Science holds the promise to make scientific endeavours more inclusive, participatory, understandable, accessible, and re-usable for large audiences. However, making processes open will not per se drive wide re-use or participation unless also accompanied by the capacity (in terms of knowledge, skills, financial resources, technological readiness and motivation) to do so. These capacities vary considerably across regions, institutions and demographics. Those advantaged by such factors will remain potentially privileged, putting Open Science���s agenda of inclusivity at risk of propagating conditions of ���cumulative advantage���. Since 2019, the EC Horizon2020 project ON-MERRIT has been investigating these issues using scientometric, sociological and other approaches to examine how these factor influence the ways in which Open Science is taken up (and by whom). As ON-MERRIT concludes, this talk will showcase diverse findings across areas including OA publishing, rewards and incentives and participatory methods. I then concludes by presenting recommendations to mitigate threats co-created with the Open Science community.