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Shares of Facebook (FB - Get Report)   closed 2.46% lower Friday to $165.98, a day after the company announced that Chief Product Officer Chris Cox and Chris Daniels, who ran the company's business development team and WhatsApp, will be departing the company as it embarks on a new privacy-led initiative. 

Cox had been with Facebook for 13 years. 

The departures were announced in a blog post from Zuckerberg in which he reiterated the social media company's new focus on being a "privacy-focused social platform."

"At this point, we have made real progress on many issues and we have a clear plan for our apps, centered around making private messaging, stories and groups the foundation of the experience, including enabling encryption and interoperability across our services," Zuckerberg wrote. "As we embark on this next major chapter, Chris )Cox0 has decided now is the time to step back from leading these teams."

Cox has played an integral role in Facebook's development, starting as an engineer on the original News Feed, building its first HR teams, leading product and design teams, running the Facebook app, and most recently determining strategy for the company's family of apps, according to Zuckerberg's post.

Facebook has faced an exodus of top executives in recent months with Instagram co-founders Kevin Systrom and Mike Krieger also leaving the social media giant.

Cox's farewell letter contained some language that may suggest that his split with the company was tied to Facebook's new direction. 

"As Mark has outlined, we are turning a new page in our product direction, focused on an encrypted, interoperable, messaging network... This will be a big project and we will need leaders who are excited to see the new direction through," Cox said in his goodbye. 

Zuckerberg also announced that Fidji Simo will be the new head of the Facebook app as part of a restructuring that will see the CEO take a more direct role in the wake of Cox's resignation.

"I do not plan on immediately appointing anyone to fill Chris's role in the near term. Instead, the leaders of Facebook (Fidji Simo), Instagram (Adam Mosseri), Messenger (Stan Chudnovsky), and WhatsApp (Will Cathcart) will report directly to me, and our Chief Marketing Officer (Antonio Lucio) will report directly to Sheryl [Sandberg]," Zuckerberg said.

Facebook is a holding in Jim Cramer's Action Alerts PLUS charitable trust.

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