The question of the extent to which EU institutions can grant powers to EU decentralised agencies has been the subject of inter-institutional and academic debate for decades. Only in 2014 did the Court of Justice itself settle the issue, confirming the constitutionality of ongoing agencification and allowing for its future development. The present article identifies a number of lessons which the EU legislature should draw from the Court’s Short-selling ruling. In addition a number of issues which have not yet been resolved by the Court but which may pose themselves in the future are identified. These relate to the nature of the discretion afforded to EU agencies, the nature of the acts which they adopt (in light of Articles 290 and 291 TFEU...