https://www.recode.net/2018/3/20/17144130/facebook-stock-wall-street-billion-market-cap

Facebook’s Cambridge Analytica data debacle could be more damaging to the company than any of its other recent missteps.

The news that the data analytics firm that helped Donald Trump get elected president was able to amass data on 50 million users without their permission has sent Facebook’s market value down nearly $50 billion since Friday. That’s the stock’s biggest two-day decline ever. As of market close on Tuesday, Facebook’s stock price was $168, about 10 percent lower than it was on Friday, according to FactSet.