$1.3 billion of value was wiped off of social media app Snapchat on Thursday.
The cause? A single tweet from reality TV star and model Kylie Jenner a day earlier.
What did she say?
Here's the tweet in full, which was sent out to her 24.5 million Twitter followers.
Perhaps realizing that many of her followers still use Snapchat – or perhaps hearing the distant rumble of stock market investors scrambling to withdraw their holdings, Jenner posted this conciliatory post a few minutes later.
What's the big deal?
The big deal is that Snapchat is fighting a constant battle for supremacy with its main rival, the Facebook-owned Instagram.
Having a major celebrity (which Jenner is, like it or not), publicly reveal that she's no longer much of a Snapchat fan – having formerly been one of its most influential users – is being read as a sign that the app is on its way down.
Her tweet caused Snapchat shares to drop 8 percent on Wall Street at one point, eventually closing 6 percent down for a total loss of $1.3 billion.
It doesn't help that Jenner now has a huge, 104.5 million following on Instagram, with this picture of her newborn getting more than 17 million likes.
As CNN reports, Snap has been criticized for its new layout, which users say is too confusing to navigate (more than it already was), with 1.2 million people petitioning the company to scrap the change.
Snapchat announced an update aimed at making it easier for users to view content they want to see, CNN adds.
The image and video messaging app has an estimated 173 million daily users, according to Business of Apps. More than half of users are under 34 years old.