The UK’s collective investment scheme (‘CIS’) sector is a key aspect of UK financial services. With the UK’s forthcoming departure from the EU, it has also become a politically salient topic, with various Member States competing to lure business to their financial centres in the light of ‘Brexit’. Brexit prompts hard choices and a key question arising for the CIS industry is whether the UK should continue to shadow EU law or whether elements of regulatory divergence could be envisaged. With a view to a greater understanding of the nuance contained within this issue, this paper considers the case study of the UK’s CIS sector, which is of considerable significance to the UK’s economy. Asset management firms invest and manage large sums of money for investors (ranging from individuals to institutions and governments); they invest in a broad range of UK and international enterprises, and make financial decisions that will affect their clients’ financial wellbeing. Asset managers offer expertise, asset diversification, and economies of scale which investors would not be able to obtain investing individually, resulting in lower transaction costs. The City of London has long specialised in asset management, and an abundance of reports quantify its importance to the UK. The sector serves a global client base; it is the second largest in the world after the US; and it is the largest in Europe. It supports an estimated 100,000 jobs in the UK, and is a key driver of funding for the UK’s economy.