Drawing on conservation of resources theory (COR), this study takes a nuanced approach to understanding job insecurity by proposing rumination as a mediator in its relationship with well-being during the COVID-19 global pandemic. The moderating role of psychological capital as a resource to buffer this negative relationship is also explored. A cross sectional study of employees in Ireland during the early months of the COVID-19 pandemic found that job insecurity rumination mediated the relationship between affective job insecurity and emotional exhaustion. There was no support for the hypothesis that psychological capital could moderate the relationship between job insecurity and emotional exhaustion. Thus, this research advances the job insecurity literature by identifying a potential mediator and moderator in the process of how employees may experience job insecurity particularly during a global pandemic.