Andrew Madgwick

Jonathan Issan is Director and Co-Head of the Crypto Trading Desk at Marex, a position he has held since February 2025. His mandate covers crypto spot and derivative flow trading, liquidity provision, and risk management.

Prior to joining Marex, Issan spent nearly seven years at Enigma Securities as Head of Quant & Electronic Trading, where he designed and built high-performance liquidity management systems including a direct market access solution, aggregator, smart order router, and internal order management system. He also implemented and monitored trading algorithms, managed automated risk systems, and led a team of quants, data scientists, and high-performance computing developers. Earlier career roles include project management at Makor, head of flow trading at Altris Ltd., equity derivative trading at Barak Capital, index derivatives trading at Phi Square Capital and Crédit Agricole CIB, and credit derivative trading at BNP Paribas. He began his career as a developer at LCL Le Credit Lyonnais. Across these roles he accumulated over 22 years of experience spanning banks, hedge funds, and trading firms, with a focus on electronic trading, market making, and quantitative strategies in equity, FX derivatives, and crypto. Issan holds a Master's degree in MIAGE from Université Paris Dauphine - PSL and an MBA in Finance & Wealth Management from MBA ESG. He is based in Tel Aviv, Israel.

Samuel Leyne is Director, Co-Head of Crypto Trading at Marex, based in Israel, a position he has held since April 2025. No further detail on his specific mandate at Marex has been disclosed publicly beyond that the role is currently being built out.

Prior to joining Marex, Leyne spent over six years at Enigma Securities, a regulated cryptocurrency liquidity provider. He served as Head of OTC Trading from April 2021 to October 2024, and before that as Head of Institutional Sales EMEA from January 2018 to August 2021. Earlier in his career, he worked as an Equity Trader at Makor Group. Between December 2015 and August 2018, he served as a combat soldier in the Golani Brigade of the Israel Defense Forces, completing an eight-month combat training programme. His total professional experience spans approximately eleven years.