Shares of Twitter dropped nearly 19 percent this afternoon after an apparent leak of its earnings report, which was scheduled to be released after the financial markets closed. The company missed analyst expectations, bringing in $436 million in revenue, lower than the expected $456.8 million. However, it had a non-GAAP earnings per share of 7 cents, compared with an expected 4 cents.

For those on Wall Street, the biggest question about Twitter over the last few quarters has always been how quickly it can grow its user base. Today, the company said it had added 14 million new users, a 4.9 percent jump over the 288 million it reported a quarter earlier.

At the core of Twitter’s increased revenue, as has been the case in recent quarters, is its advertising unit, which hit $388 million, an increase of 72 percent year over year in Q1. Its mobile advertising accounted for 89 percent of its total ad revenue.

Twitter is always going to face scrutiny for its user growth, given that sharp boosts in active users likely mean a corresponding boost in revenue. The company’s Q1 user growth of 4.9 percent, then, likely will help put Wall Street’s concerns to rest, at least for a while. Clearly, though, investors were very concerned by its revenue number, which was 4.5 percent lower than what analysts had expected.

All that aside, Twitter had a noteworthy quarter. Over the last three months, it launched Periscope, the livestreaming mobile app it purchased. It also released a new-look home page aimed at luring in new users. And it partnered with Foursquare to add more precise location information to tweets.

Company earnings are normally released after 4 p.m. ET, when the markets in New York close. But Twitter’s Q1 report was apparently leaked around 3:30 p.m. ET by the financial data analysis company Selerity. Trading in Twitter’s shares were halted temporarily, until Twitter officially released its earnings numbers a few minutes later.

Twitter’s shares were up about 2.44 percent in after-hours trading.