Twitter said Wednesday it lost another $90 million during the final three months of last year, preserving its profitless history.

Twitter may be one of the top social media sites, but its user base isn’t growing as fast as competitors Facebook and Instagram.

The company's reported no user growth at all in the fourth quarter, the clearest signal yet that the one-time trendsetter is struggling to remain relevant. That leaves it with 320 million monthly users - roughly one-fifth the size of Facebook.

Its biggest hurdle is figuring out how to make a profit.

Investors don’t seem to be confident. The stock, which was worth $50 a share in April, dropped below $15 for the first time this week.  If the shares trade similarly in Thursday's regular session, it will mark a new low.

The company has recently made several changes to its user interface.

It introduced the Moments tab, which it says makes it easier for new users. But the feature has failed to catch on. Today, it announced a feature that will let users first see tweets in their feed it thinks will be of higher interest. Over the weekend, the hashtag #RIPTwitter was trending in the U.S.

It's unclear how those strategies will increase revenue.

Data curated by FindTheCompany
Data curated by FindTheCompany