DE Shaw, an investment and technology development firm, announced today that Ángel Ubide and Brian Sack have joined as senior vice-presidents and co-directors of global economics in the firm's discretionary macro investing unit. Dr. Ubide joins the firm from Tudor Investment Corporation, where he was director of global economics. Dr. Sack joins from the Federal Reserve Bank of New York, where he was an executive vice-president and served as a special adviser to the bank's president.