National Holdings Corporation announced that Robert B. Fagenson has resigned from his position as co-chief executive officer of the company as of January 31, 2017 and, as of such date, Michael Mullen, who also served as co-chief executive officer of the company, has assumed the title of chief executive officer of the company. Mr. Fagenson will continue to serve as a member of the board of directors of the company and as the vice chairman of the board.