https://www.theverge.com/2018/3/19/17139642/facebook-stock-fall-market-cap-data-breach-cambridge-analytica

Facebook’s stock has tanked after revelations that the company had shared the data of up to 50 million users with the political data analytics company Cambridge Analytica. By noon ET on Monday, it’s dropped by nearly 7 percent — the most that Facebook has fallen in a single day in over five years.

Within the indexes for major tech and financial companies like the Nasdaq 100 and the S&P 500, Facebook was the biggest loser today, reports Bloomberg. The loss cut into Facebook’s market capitalization by around $43 billion, or $15 per share. It began steadily climbing since the mid-day mark. Other publicly traded social network companies are also seeing the effects, with declines on both Twitter and Snap this morning.