Facebook Inc.'s widely held stock plummeted Thursday in one of the worst dollar declines in stock market history after the company warned that its growth is slowing amid privacy concerns and other controversies at the social media giant.
Other major technology stocks also fell.
Facebook tumbled $39, or nearly 18 percent, to $178.50 a share in midday trading. The stock had dropped more than 20 percent in after-hours trading Wednesday following Facebook's second-quarter earnings report.
The sharp decline wiped $113 billion from Facebook's overall stock-market value, lowering it to $517 billion. The stock was trading near record highs before the earnings report.
The loss was on track to be the largest daily dollar decline for a publicly held U.S. company in history, topping a $91-billion drop of Intel Corp. stock in 2000, Bloomberg reported.
The drop also erased $15.7 billion of Facebook Chief Executive Mark Zuckerberg's wealth, which is tied to his ownership of company shares. But Zuckerberg's Facebook stake was still worth about $71 billion.
The Nasdaq composite index, which is laden with tech shares, fell 0.83 percent to 7,866.06 by midday Thursday. The blue-chip Dow Jones industrial average gained 0.5 percent to 25,547.44.
Although Facebook is still growing _ its second-quarter advertising revenue surged 42 percent from a year earlier _ its revenue and average daily visitors fell short of analysts' projections, which was attributed partly to disenchantment with the public scandals over privacy and content that have enveloped Facebook in recent months.
"We're continuing to focus our product development around putting privacy first, and that's going to, we believe, have some impact on revenue growth," David Wehner, Facebook's chief financial officer, told analysts on a conference call Wednesday.
The issues prompted Zuckerberg to testify in front of U.S. lawmakers in April, where he was grilled about Facebook's protection of its users' private information.
The Menlo Park, Calif.-based company also said it expected quarterly revenue growth to slow over the rest of the year.
Facebook's outlook prompted investors to question the valuations of other high-flying tech stocks, many of which had shown substantial gains in the prior 12 months.
Twitter Inc. dropped 3.3 percent Thursday, and Snap Inc., the parent of Snapchat, fell 1.6 percent. Amazon.com fell 1.9 percent, but Alphabet Inc., the parent of Google, rose 0.3 percent.
