Photo credit: pixinoo / Shutterstock

For more than a decade now, Facebook has been one of the fastest growing companies in the world, and its founder Mark Zuckerberg has rapidly become one of the richest people alive. All along, there’s been a general perception that Zuckerberg could do no wrong. Now, though, we’re starting to see that his empire is far from invincible. Facebook’s stock lost nearly 20 percent of its value in a single day last week, which has led to questions about the long-term viability of the business.

On Thursday, July 26, Facebook began the day with a total valuation of $630 billion; by day’s end, that figure had fallen to $510 billion. As MarketWatch noted, it was by far the company’s biggest single-day decline ever, and there’s reason to believe that trouble will continue mounting for the company in the weeks to come.

“The guidance, it’s nightmare guidance,” said Daniel Ives, head of technology research at GBH Insights. “If you look at their forecast for the second half of the year in terms of user growth, and the expense profile, it refuels the fundamental worries about Facebook post-Cambridge Analytica.”

As the Cambridge Analytica scandal has made headlines, and investors have seen other signs of low-quality news content taking the site by storm, there’s been an understandable dip in people’s willingness to invest in the Facebook brand. Zuckerberg also made headlines recently when he said he would decline to crack down on offensive content such as Holocaust denialism.

Additionally, there is reason to be concerned about the company’s profitability. Facebook has traditionally been able to bring in huge revenues and keep overhead low, but Zuckerberg’s expenses have increased this year as he’s made a bigger investment in security.

In short, there are reasons to be concerned about Facebook’s long-term outlook. For now, though, the company still appears well positioned to eke out a profit.

“There’s still unprecedented scale, the best ad tech in the industry,” said Jesse Math, Facebook lead at advertising agency PMX. “In the short term, Facebook is still viable.”