This article provides first evidence on the capital market effects of the EU Taxonomy Regulation (TR). The TR introduced a new classification scheme to identify companies with environmentally sustainable economic activities. The results offer support for a significant estimated TR alignment premium, compatible with the interpretation that investors already apply the TR and allocate capital to TR-aligned companies. This effect strengthens with an increase in investor attention. We also find significant cross-sectional variation in abnormal stock returns surrounding the publication date of the TR conditional on the degree of estimated TR alignment. Traditional ESG ratings cannot explain the TR premium.