Sales executive Sean Sullivan, 58, of New Canaan CT, passed away on Saturday, November 13 at Mt. Sinai Hospital in New York City. His cause of death was post-surgery complications arising from the removal of a brain tumor. Sullivan – affectionately known as “Sully” – was a pioneer in the securities trading technology industry, and a gifted salesman, with a career spanning over three decades and throughout unprecedented innovation across the industry. Sean was the beloved son of his predeceased parents Thomas J. Sullivan, Marianne Sullivan, and Patricia M. Sullivan.