Twitter’s stock reached new historic lows this week, briefly sliding under the $14 mark Tuesday morning, only to settle at $14 at the close of markets. This most recent dip came after Twitter’s Q1 earnings release last week, which once again disappointed investors.

But the severity of it — Twitter’s shares lost 21 percent within the last seven days — has as much to do with what Twitter investors get to see every time they look into their magic mirror: A striving Facebook, which beat the market’s expectations on revenue with its own earnings report last week.

In many ways, Facebook has become the anti-Twitter, pointing to everything that could have been, and adding to a vicious circle: Everything that Twitter wants to do, Facebook does better, bigger, faster — leaving little patience for investors waiting for a turnaround.

Facebook Grows Faster, Makes Money

Twitter’s management has long struggled to control the narrative around the company. Last week’s earnings release was no different. After some quarters without any user growth, Twitter finally started to add monthly actives again, growing its user base 3 percent year-over-year. The company also grew its revenue, and even managed to cut its losses by 50 percent.

Investors however weren’t happy. Not only did revenue growth slow significantly, but U.S. user growth still flatlined, despite a new marketing campaign and new products that were supposed to make Twitter more accessible to new and casual users.

Still, all of that may not have hurt quite as much if Facebook hadn’t done so spectacularly well. Just one day after Twitter’s release, Facebook revealed 15 percent monthly active user growth year-over-year, and almost tripled its net profits.

The Facebook Live Effect

Facebook doesn’t just outperform Twitter on numbers. The social network continuously manages to succeed in areas where Twitter has been struggling.

Facebook rules the messaging market with not one but two billion-user properties while Twitter hasn’t been able to take advantage of direct messaging within its apps. Twitter slept on photo sharing; Facebook grew Instagram to be bigger than Twitter. Twitter has been struggling with ways to share longer content within the limits of its 140 character limit . Facebook has been embracing publishers with open arms, offering them Instant Articles and other tools to keep readers glued to its platform.

And now, Facebook is seemingly outperforming Twitter in that one area that still was a silver lining for the struggling company: live video. Twitter has seen a lot of growth in social live video ever since launching Periscope a year ago. Periscope users started 200 million broadcasts during its first year, with viewers watching close to one million hours on video every single day.

But Facebook managed to get all the attention, and a huge boost in momentum, ever since giving broadcasters more tools — and in some cases money — to go live last month. Not only have publishers flocked to the platform, they’ve also seen unprecedented audience sizes, with more than 800,000 people tuning in during peak times when BuzzFeed decided to blow up a watermelon on its Facebook page last month.

Rebranding alone is not enough

All of this makes Twitter investors understandably nervous, and has Twitter struggling to distance itself from the juggernaut. Just last week, Twitter switched its app from the “social networking” category in Apple’s App Store to the “news” category, where it now ranks first.

But in order to succeed, Twitter needs to not just relabel what it does, but actually do something that sets it apart from Facebook — and investors rightly question whether the struggling company still has the chops to outdo its huge nemesis.