Several international initiatives, including the World Economic Forum (WEF), aim to constitute biodiversity loss as a material risk to the 'bottom line' calculations of investors and insurers. The WEF claims that while no sector 'escapes untouched by some form of biodiversity risk', such risks can be transformed into opportunities, and ideally, profit. I trace the key actors, reports, and methodologies producing 'biodiversity loss as risk', and outline some of the challenges, paradoxes and implications of this transformation. In particular, I show how biodiversity loss is a difficult to transform into an individuated risk that can cause firms to act otherwise. However, new calculative devices are emerging to help individuate and calculate biodiversity risks for firms. In this paper I focus on two of such devices, the Integrated Biodiversity Assessment Tool (IBAT) and the Corporate Ecosystem Service Review (CESR). Both tools aim to render biodiversity loss legible in the language and metrics of financial risk. These tools devised to produce biodiversity risk, I argue, have effects. They are changing the way that conservation knowledge is produced, producing new spaces for investment and disinvestment, and are also re-defining the very subject of conservation. (C) 2012 Elsevier Ltd. All rights reserved.