Twitter, led by co-founder Jack Dorsey, said on Tuesday monthly active users ticked up to 310 million in the March quarter, but revenue fell short of expectations. Facebook has about 1.6 billion users, and is growing quickly.
The company's shares fell nearly 17 percent to $14.81 on Wednesday, their biggest single-day percentage drop since August 24. In the past 12 months, the company's market value has declined by more than $26 billion.
Analysts said the benefits from the improvements that Twitter had made to its services might come not come in soon enough.
"It needs to prove that it can fix its product issues before users leave and go to other networks for good," Macquarie analyst Ben Schachter said in a note.
The outlook does not look good either. The San Francisco, California-based company forecast second-quarter revenue widely below Wall Street expectations.
Of the 44 analysts covering Twitter, at least 18 cut their price targets. Pivotal Research was the most bearish, slashing its target to $27 from $39. JP Morgan also lowered its rating to "neutral" from "overweight".
The median price target on Twitter is $18.
"It's becoming abundantly clear that Twitter now not only suffers from user fatigue, but advertiser fatigue as well ... Twitter should be investing aggressively on marketing, R&D and potentially M&A, in an effort to stay a relevant public company," Moffett Nathanson analysts said.
Only two brokerages remained bullish - Goldman Sachs and Mizuho Securities raised their price targets.
Mizuho analysts said some products could drive growth later this year or in early 2017, while Goldman analysts said there was "significant value in Twitter's user base, content ... that a stable management team and focus on product should be able to unlock."
Too little, too late?
The company's stock has lost about two-thirds of its value over the past year, but is still much more expensive than most of its peers.
Twitter has improved the way tweets appear even when a user is not logged in and tweaked timelines so that some tweets are prioritized over others.
It has also signed a content streaming deal with the National Football League that could help the social media site expand its user base.
Video has also been a recent focus for the company. Twitter said on Tuesday its users were spending more time watching and sharing video, but added that advertisers' budgets had not yet shifted from legacy advertising products such as promoted tweets.
"... the shift from legacy promoted tweets to higher performance ads led to cannibalization of budgets," Canaccord Genuity's Michael Graham said.
"We think this could be a risk for the next quarter or two, adding to the depth of the operating trough we already expected until product improvements can drive sustained MAU growth."
© Thomson Reuters 2016