The tech world was rocked by news Monday night that Instagram co-founders Kevin Systrom and Mike Krieger would exit the company, sending shares of parent company Facebook, Inc. (FB) to plunge in early hours trading Tuesday.

Facebook shares dropped more than 2 percent before a late-morning rebound. The drop began in pre-market trading and continued after markets opened, with the social media firm’s stock price dropping as low as $161.50 per share.

Systrom made the move official in a press release posted on Monday night, after it was originally reported by the New York Times. The statement was light on specifics, but hinted at he and Krieger’s alleged dissatisfaction with their places within the Facebook corporate hierarchy.

“We’re planning on taking some time off to explore our curiosity and creativity again,” Systrom wrote. “Building new things requires that we step back, understand what inspires us and match that with what the world needs; that’s what we plan to do.”

Facebook purchased Instagram for $1 billion in 2012. Since then, reports indicate that tensions mounted between Instagram’s founders and Facebook CEO Mark Zuckerberg. Disagreements between Systrom and Zuckerberg over product features and the level of autonomy Instagram had within the company could have contributed to the founders leaving, according to TechCrunch.

Instagram has been a boon for Facebook, which has faced controversy this year from its namesake social network. The Cambridge Analytica data scandal tied into concerns over how the site would manage important upcoming elections. The site is also embroiled in lawsuits regarding its treatment of content moderators and alleged gender discrimination in employment ads.

Still, Instagram soldiered on, reporting strong user growth over its main rival, Snapchat.

Shares of Facebook have seen a steady decline since its all-time high of $218.62 on July 25.