The company’s stock plunged 19 per cent in early US trading on Thursday.
The social media company’s financial results, released late on Wednesday, fell short of Wall Street expectations as the company continues to grapple with privacy issues.
It also warned that revenue would decelerate as it promotes new products.
Facebook had 2.23 billion monthly users as of 30 June, up 11 per cent from a year earlier, but well short of what industry analysts had been expecting.
The results are from the first full quarter following the revelation of the Cambridge Analytica privacy scandal. The company is also contending with European privacy rules that went into effect in May.