Firms need a fully authorised legal entity located in the EU27 to operate after Brexit.
Profit for 2018 will be hit by £10m due to Brexit and MIFID II.
The exchange operator plans to establish a post-Brexit bourse in the Dutch capital.
The association said international debt capital markets could fragment.
Firms should ensure they have the correct regulatory permissions ahead of time.
MHR Analytics notes investment in critical 'big data' technologies is often overlooked.
Euro clearing may be forced to move from London after Brexit.
Regulators are analysing MiFID II data and will make changes.
CFTC and Bundesbank argued over the supervision of euro clearing.