Scott Johnston is the Chief Administrative Officer of Citadel. Prior to becoming CAO in 2018, Scott served as Chief Operating Officer of Citadel Securities. Scott joined Citadel Securities in 2017 from Tower Research Capital, where he was a partner and COO responsible for business development, operations and business management. Prior to joining Tower, he was Managing Director and Chief Information Officer at the Chicago Mercantile Exchange (CME), responsible for GLOBEX and clearing technology. During his time at the CME. Scott is a graduate of the University of Michigan.