Threads is a standalone, camera-first messaging app that will allow users to stay connected with close friends through photo and video messages.
"It opens directly to the camera and allows you to add shortcuts, so you can share what you're doing in just two taps," Facebook wrote in a blog post introducing the service.
Like Facebook and Instagram Stories, Threads is another direct threat to Snap's operating model, and the release sent Snap shares tumbling 4.8% to $14.09 Thursday afternoon.
Facebook shares, meanwhile, were rising 2.5%.
Threads builds on Instagram's "close friends" feature that allows users to select specific friends to share their posts with.
Snap shares have rebounded nicely in 2019, climbing 145% year to date. However, the stock is down nearly 20% over the past five days and shares still trade below the company's initial offering price of $17 back in 2017.
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