Barry Gosin, who grew Newmark from a ragtag brokerage to one of the world’s top CRE service firms, is stepping down after a five-decade run. Gosin, 75, will step down as CEO at the end of the year, Newmark announced Friday. He will stay on as chairman through at least 2029, and the company’s board of directors is working to identify a successor. “I have spent nearly my entire career at Newmark, working alongside an exceptional team whose dedication, talent and commitment have made the Company’s success possible,” Gosin said in a statement. The burning question now is who will replace Gosin as head of Newmark, the fourth-largest commercial real estate services firm in the world.