(Reuters) - Robo-adviser Betterment LLC said founder Jon Stein will step down as chief executive officer on Tuesday and will be replaced by former ViacomCBS Inc executive Sarah Levy. Stein, who launched the company in 2010, will stay on as chairman and serve on the board. Levy started her career at Walt Disney Co and was most recently chief operating officer at Viacom Media Networks. She has been an operating adviser at Betterment for the last several months, the company said. "With her experiences leading large public companies, Sarah is the right executive to lead Betterment now, as we contemplate a transition from private to public in the coming years," Stein said in a blog post here. Betterment, which provides robo-advising and cash management services, has about $25 billion in assets under management and more than 500,000 customers. The popularity of robo-advising startups has prompted established firms, including Charles Schwab Corp and Morgan Stanley, to launch competing services. The moves from larger firms have, however, raised questions as to whether independent robo-advisers can grow at a sufficient scale to become profitable and survive, given the low fee model.