(San Francisco)

Yesterday was an absolutely monstrous one to be an investor in Facebook. In what will likely go down as a history-making day for the company, Facebook shares dropped a whopping 20% yesterday, equating to more than $100 bn of value lost. The huge losses were sparked by weaker than expected revenue growth as well as flat or falling user bases. That sent the stock down 7%. However, it was the guidance provided on a conference call that really spelled doom. The company’s CFO said that he expected weak revenue growth to continue, while costs were expected to rise 50-60% this year.

FINSUM: The big rise in costs is coming because Facebook is hiring 20,000 staff to increase cybersecurity. The need to do so does not bode well for the stock or the tech sector generally.