Martin Sommer Principal, Oliver Wyman Martin Sommer is a Principal in Oliver Wyman’s Corporate and Institutional Banking practice. He has worked in depth with leading financial institutions, with a focus on strategy and innovation projects in Corporate and Transaction Banking across UK and EMEA. Martin co-leads Oliver Wyman’s market-leading annual Transaction Banking benchmarking platform, which delivers detailed performance metrics to the largest global and regional transaction banks. He has also authored Supply Chain Finance: Riding The Waves, which looks at the latest developments in the Supply Chain Finance industry.