Facebook is facing the biggest single-day loss in stock market history. Here are all the reasons why.

Facebook’s shareholders finally awoke Wednesday to the mounting problems that have beset the social network for more than two years — wiping $120 billion off the company’s value in the space of a couple of hours.

The company has been hit by numerous controversies in recent years, but throughout that time, two things have remained constant — its ability to make piles of money from advertising and add large chunks of the world’s population to its user base.

That changed Wednesday when Facebook reported lower-than-expected revenue, slower user growth and, most worryingly for investors, a warning that profits would continue to decelerate throughout 2018.

Facebook’s stock took a hit in after-hours trading, but seemed to stabilize. Then the company’s chief financial officer David Wehner told an earnings call that he expects revenue deceleration “in the high single digits for the next couple of quarters.”

Wall Street was not happy:

When the bell rings in the Nasdaq Thursday, all eyes will be on the FB ticker to see how investors react, with the company likely to break the record for the biggest single-day loss in stock market history.

• Population: Facebook is huge. It has 2.23 billion monthly users, which for context is roughly every Christian on the planet. Yet there are only 3 billion people who can access Facebook, so the company has already captured 75 percent of the addressable market. With little hope of getting into China, and efforts to help boost internet penetration in hard-to-reach places stuttering, a slowdown in growth was always going to happen.
• Cambridge Analytica: This isn't the first time Facebook’s stock has tanked this year. After it was revealed in March that 87 million Facebook profiles were harvested by data firm Cambridge Analytica for “psychographic profiles,” shares fell by 24 percent. However, less than two months later all $134 billion of its lost value had returned, with investors believing the controversy would have no lasting impact. They were wrong.
• GDPR: Regulators in Europe last month introduced some of the strictest privacy laws in the world, putting pressure on companies such as Facebook to ensure the information they stored on users was safe, easily accessible and easy to delete. Facebook said it had everything in place to comply with the new laws and the impact would be negligible. Yet on Wednesday Facebook revealed that in the first month since GDPR was introduced, it lost one million users in Europe — a drop in the ocean compared to the 376 million users it still has in the region, but a warning that worse may be to come.
• Investigations: In the U.K., the Information Commissioner’s Office has already hit Facebook with the maximum allowable £500,000 fine for its part in the Cambridge Analytica scandal. But that is just the beginning. In the U.S., the Justice Department, the FBI, the Securities and Exchange Commission, and the Federal Trade Commission are all conducting probes into the social network. It is also facing investigations by the attorneys general of New York and Massachusetts. Elsewhere, the company is facing scrutiny from the European Parliament as well as regulators in Australia.
• Fake News: Facebook’s role in Donald Trump’s 2016 election has been widely criticized. The company has admitted that Russian-based actors infiltrated its network to spread disinformation and forment division, but it's unclear if the company will be able to stop a repeat during this year’s November midterms. Facebook CEO Mark Zuckerberg has been grilled by Congress but his non-answers failed to satisfy lawmakers, meaning trust in the company has been damaged — possibly irrevocably.
• Genocide: Fake news is bad, but being accused — by the U.N. — of helping to facilitate genocide is an order of magnitude worse. That is exactly the charge in regards to Myanmar, where the social network has been used to spread hate speech and incite violence toward the minority Rohingya population. Similar problems have been reported in Sri Lanka, Cambodia, and Vietnam.
• WhatsApp: Operated mostly as a separate entity to Facebook, WhatsApp is still part of the company — and it is now drawing controversy of its own. With 1.5 billion users, WhatsApp is much more popular outside the U.S. and in particular in countries like India. Here, however, it has become a conduit for fake news and incendiary rumors, which have led to the lynching of dozens of people. While Facebook is taking steps to stop this, the encrypted nature of the messaging app makes it difficult to see exactly what is being spread on its network.

Cover image: Mark Zuckerberg, chief executive officer of Facebook, checks his phone during the annual Allen & Company Sun Valley Conference, July 13, 2018 in Sun Valley, Idaho. (Drew Angerer/Getty Images)