https://www.theverge.com/2018/7/26/17615330/facebook-earnings-forecast-user-growth-revenue

On Tuesday, for the first time in three years, Facebook failed to meet Wall Street’s expectations for revenue and user growth. The company’s user base of 185 million users in the United States and Canada remained flat over the last quarter, and added just 22 million users worldwide — the lowest number of additions since at least 2011. The stock declined more than 20 percent.

On one hand, you couldn’t call the news a complete surprise. As Mike Isaac noted, Facebook has warned for months that the changes it was making to the News Feed would reduce its growth. And Mark Zuckerberg told analysts that the company’s efforts to fix its platform would have a meaningful, and negative, effect on revenue.