Wall Street brokerage firm Needham & Company downgraded the social media giant to a hold rating on Monday, amid worries of a continued management exodus, Laura Martin, a Needham analyst, told CNBC.

“We are concerned that regulatory, headline, and strategic pivot risks will negatively impact Facebook’s valuation more than investors currently believe due to the negative flywheel created by Networks Effects,” she said. “A Negative Network Effect suggests that departures will continue, and since we believe that people are a key competitive advantage of FAANG [Facebook, Amazon, Apple, Netflix, and Google] companies, this implies accelerating value destruction until senior executive turnover ends.”

Bank of America Merrill Lynch analyst Justin Post shared Martin’s concerns, according to CNBC. “While we think Facebook has a significant pool of talent to operate the business, and Cox’s departure has been considered for some time given long tenure, the timing raises some concern around internal [dissension] on Zuckerberg’s vision for Facebook,” Post said.

A number of top managers have left Facebook in recent months, including chief product officer Chris Cox and Instagram co-founders Kevin Systrom and Mike Krieger. CNBC notes that such departures are compounded by other issues with Facebook itself, including a nearly 24-hour outage last week, and the livestream of the New Zealand terrorist attack.