In 1963, Levitt joined the brokerage firm Carter, Berlind & Weill, founded three years earlier by Sanford I. Weill. Levitt's name was eventually added to the firm's when it was renamed Cogan, Berlind, Weill & Levitt in the mid-1960s; through a series of mergers the firm eventually evolved into Shearson Loeb Rhoades. This experience with retail customers was a source of his interest in the small investor. After sixteen years on Wall Street, Levitt became the Chairman of the American Stock Exchange (AMEX) in 1978. In 1989, he left the AMEX to serve as Chairman of the New York City Economic Development Corporation until 1993.