This Practice Note considers the role of prime brokers and also sets out a brief overview of some of the services prime brokerage firms typically provide to their clients, (including alternative investment funds (AIF) and their managers), with a particular focus on AIFs in the UK and the EU. It also sets out an overview of regulatory areas relevant to prime brokers (for example, material EU changes under Directive (EU) 2024/927 (AIFMD II), including updated depositary, disclosure and reporting requirements; and current UK supervisory focus on disclosure quality, margining, operational resilience and non-bank leverage). What is prime brokerage? ‘Prime brokerage firms’ (investment banks or other financial institutions) may provide ‘prime brokerage services (both terms are defined in the Glossary of the FCA Handbook (FCA glossary) , as further detailed below), for instance to an AIF or other large investment client. As noted in a January 2025 speech published by the Prudential Regulation Authority (PRA) delivered by its Executive Director for Authorisations, Regulatory Technology and International Supervision, Rebecca Jackson on prime brokerage (Rebecca Jackson speech), in practice, prime brokerage