This article explores how the meanings and values of diagnosis are being reconfigured at the interface between technological innovation and imaginaries of precision medicine. From genome sequencing to biological and digital 'markers' of disease, technological innovation occupies an increasingly central space in the way we imagine future health and illness. These imaginaries are usually centred on the promise of faster, more precise and personalised diagnosis, and the associated hope that if detected early enough disease can be effectively treated and prevented. Underpinning and reproduced through these narratives of the future is a re-conceptualisation of diagnostic processes and categories around the anticipation of future risk, as noted by recent theoretical developments in the sociology of diagnosis and related disciplines. Adding to this literature, in this article we explore what makes these emerging diagnostic arrangements valuable, to whom and how. Drawing on interviews with experts involved in the development of digital biomarkers for Alzheimer's disease, we trace how multiple and at times conflicting applications of the tools, and the value(s) attached to them, are coproduced. We thus ask what possibilities are pursued, or foreclosed, through the work of imagining the future of diagnosis.