Facebook acknowledged for the first time its teen user base may be headed south, after claims from industry analysts, pundits and users. Facebook CFO David Ebersman revealed on the company's quarterly earnings call on Wednesday that it has been tracking a slight decrease. 

"Youth usage among US teens was stable overall from Q2 to Q3, but we did see a decrease in daily users partly among younger teens," Ebersman said.

Ebersman didn't define what he meant by young teens, but it's believed to be the 13 to 17-year-old bracket Facebook has been trying so hard to hang on to. In recent weeks the company changed a security policy allowing teenagers to post publicly like adults. "While only a small fraction of teens using Facebook might choose to post publicly, this update now gives them the choice to share more broadly, just like on other social media services," Facebook said at the time. 

The policy change seemed like a battle cry against other social networks on the web, specifically Twitter, Snapchat, and Facebook's own Instagram. Teenagers have been flocking away from Facebook, which many blame on parents joining Facebook and ruining the teens' getaway. 

"I don't think there's really a decline in usage," said Ryan Orbuch, 17-year-old behind award winning Get Finish app. "But there's a big decline in those who enjoy using it. There’s a lot of ugh-Facebook-just-because-I-have-to type thing. It's way fewer teens who are excited/see it as new/cool. Facebook is totally utilitarian now."

Facebook executives don't see an issue with the drop, however. “This is of questionable significance, but we wanted to share this with you now because we get a lot of questions about teens,” Ebersman said. 

Investors remain concerned about the teen market. As Facebook earnings hit, the company's stock skyrocketed 15 per cent. When Ebersman began talking about the slight decline in the teen market, Facebook stock's gains were wiped out and fell flat. 

However, user growth is on the up-and-up for Facebook, the earnings revealed. The social network has now passed 1.19 billion monthly active users, with daily active users passing 728 million on average during September 2013. As for its number of mobile monthly active users, Facebook hit 874 million, with daily mobile active users passing 507 million on average for September 2013.

Still, once the teens leave and move on, won't the adults follow?