Simon Yates, global head of equity derivatives at Citigroup, is set to leave the US bank to become chief executive of the New York-based hedge-fund firm Two Sigma Investments in September. According to a memo seen by SRP, the New York-based banker will join as chief executive of Two Sigma Securities, the hedge fund firm's market-making division. Citi's global head of equities in New York, Derek Bandeen, said in a memo that Yates intends to resign from the firm to pursue other interests, and th