The reality TV star, who has a formidable social following across social media platforms, tweeted about the app's unpopular redesign Wednesday, saying that she rarely uses it anymore.
"Sooo does anyone else not open Snapchat anymore? Or is it just me ... ugh this is so sad," she wrote.
Later, she added, "Still love you tho snap," but it seems the damage may have already been done.
"Our goal with the recent redesign is to make Snapchat more personal for everyone," a Snapchat spokesperson told ABC News. "This new foundation is just the beginning and we will always be grateful for any feedback from our community as we roll out new products."
At 1:30 p.m. ET on Wednesday, Snapchat's stock was at $19.02, and after Jenner's tweet later in the day, it plummeted for most of Thursday. According to Bloomberg, the tweet could have cost Snapchat $1.3 billion in market value.
Jenner, 20, is not the only person to take issue with Snapchat's redesign, however. More than 1.2 million people have signed a petition on Change.org begging for it to be removed, prompting Snapchat to respond, "We completely understand the new Snapchat has felt uncomfortable for many."
"This new foundation is just the beginning, and we will always listen closely to find new ways to make the service better for everyone," read the company's statement, in part. "We are grateful for your enthusiasm and creativity. We are very excited for what’s ahead."