In line with an increase in sustainability-related reporting requirements, such as the Corporate Sustainability Reporting Directive (CSRD) in the European Union, it is important to further the academic understanding of the reporting of sustainability information, how auditors provide assurance on this information, and how investors perceive this information and incorporate it into their valuations of organisations. The main goal of this PhD project is to examine how the reporting of sustainability information impacts investor perceptions and valuations, and to investigate what role the auditing of the sustainability information plays in this relationship. Specifically, for the first project that is part of the overall PhD trajectory, the aim is to investigate investors’ credibility perceptions of sustainability reports, in light of different reporting formats.