Mark Chen has been appointed co-head of equity derivatives for the Americas at Deutsche Bank, in New York. Chen will work alongside fellow co-head, David Silber , who joined the German bank from Citi and reports to Brad Kurtzman, head of equities, Americas, also in New York. Chen also joins from Citi, where he held a number of roles in equity derivatives trading, most recently as head of flow derivatives trading. Chen joined Citi from Citadel Securities, where he was vice president, equity deri