Digital disruption in the form of new business models may include changes to the ecosystem of a firm. This paper defines the ecosystem as external stakeholders interdependent on a focal firm, and shows how such stakeholders play different roles as disruption unfolds. Focusing on incumbent firms and their ecosystems, this paper describes and categorizes the role of ecosystem stakeholders across various stages of disruption. Two cases on the disruption caused by digitalization in the advertising sector are analyzed. A processual ecosystem stage model is developed including the following roles: reassuring, questioning, unbalancing, and settling. These roles point at the reliance on past stakeholders during disruption, and show how new stakeholders come into play. Most disruption research has focused on how new actors replace incumbent firms or the sector-level disorder. The ecosystem lens centered on an incumbent brings a fresh perspective on such firms' efforts to survive and shows how interdependencies in the ecosystem play out when disruption takes place. The processual stage model, which delineates the different roles of ecosystem stakeholders during a disruption, offers valuable new insights to the existing disruption literature.