Simon Firth

Practice Areas

Simon is a leading authority on derivatives, specialising in the structuring and documentation of derivatives transactions and advising about issues arising in relation to derivatives and the financial markets generally.

Simon led the team advising the English administrators of the Lehman Brothers companies on their derivatives, repo and stock lending positions and has been involved in some of the market’s most significant cases involving derivatives.

He is responsible for the updating of ISDA’s English law netting and collateral opinions and was part of the team that drafted the 2021 ISDA Interest Rate Definitions. In 2024 he undertook a review, at the request of ISDA, of the operation of the Credit Derivatives Determinations Committees. His report made a number of recommendations for the reform of the determinations process.

Professional Memberships

Simon is a member of the financial markets law committee and a Visiting Professor of the University of Law.

Publications

Firth on Derivatives Law and Practice, Sweet & Maxwell (looseleaf), the leading text book on English derivatives law; and

“The English Law Treatment of Lehman’s Derivatives Positions”, in Bank Failure: Lessons from Lehman Brothers, Oxford University Press, March 2017