Twitter's first-quarter earnings report crushed expectations, sending the stock surging 15.6% Tuesday.

The pop added $4.1 billion to Twitter's market cap, bringing it to $30.5 billion.

Here's what Twitter reported Tuesday:

Earnings per share: adjusted 37 cents vs. 15 cents expected in a Refinitiv survey of analysts

Revenue: $787 million vs. $776.1 million expected in the Refinitiv survey

Monthly active users (MAUs), excluding SMS users: 330 million vs. 318 million expected in a FactSet consensus estimate

This quarter will be the last for which Twitter reports monthly active users (MAUs), the company announced during its last earnings report. As a replacement, Twitter began to report what it calls monetizable daily active users (mDAUs) last quarter, which it said would better reflect its audience. This metric includes "Twitter users who log in and access Twitter on any given day through Twitter.com or our Twitter applications that are able to show ads," according to the company.

Twitter reported 134 million average mDAUs for the first quarter, compared with 120 million a year earlier. In the fourth quarter, Twitter said it had 126 million mDAUs.

In the U.S., Twitter reported 28 million average mDAUs forthe first quarter, compared with 26 million a year earlier. It reported 105 million average international mDAUs for the first quarter, compared with 94 million a year earlier.

The shift to a new metric came after Twitter reported MAUs that fell short of analyst estimates for two straight quarters during its fiscal year 2018. Twitter previously blamed the shortfall in part on a July 2018 purge of "locked" accounts that was meant to get rid of bots and fake users, among other factors. Twitter said the 330 million average MAUs it reported for the first quarter was a decrease of 6 million year over year.

Twitter forecast second-quarter revenue of $770 million to $830 million, compared with analyst estimates of $783.9 million to $853.6 million in the Refinitiv survey. The company reiterated its announcement from last quarter that it expects cash operating expenses to increase about 20% year over year in 2019 as it continues to invest in "health, conversation, revenue product and sales, and platform."

Twitter's stock slid after its previous earnings report when it provided light guidance for the first quarter, but it is still up about 10% over the past 12 months. Twitter has been toying with the best way to optimize the experience on the platform for user well-being rather than purely based on engagement metrics. CEO Jack Dorsey told Rolling Stone in an interview published in January that his team has considered "what happens if we remove the 'like' counts from tweets."

Twitter rolled out a public beta test through a separate app last month where it has tested new features, including hiding some replies by default to unclutter conversations and hiding engagement options until a user taps on a tweet, TechCrunch reported.

On a call with analysts following the report, Dorsey said the prototype "twttr" app results so far have been promising, but he did not provide a concrete timeline for the broader release of new features.

"Generally, most of the people that have been testing the prototype app prefer it over the main Twitter production app," Dorsey said. "So it's shown that we're heading in the right direction, but we still have some work to do before we feel confident that we should put it in production."

In Twitter's earnings release, Dorsey said the company is "taking a more proactive approach" to abuse on its platform.

"We are reducing the burden on victims and, where possible, taking action before abuse is reported," Dorsey said. Twitter now removes 2.5 times more tweets sharing personal information, and about 38% of abuse tweets taken down each week are detected by machine learning models, he said.

On the analyst call, Dorsey addressed a question about regulation, saying Twitter is "completely open to regulation where it makes sense."

"Regulations like GDPR have been a net positive, and not just for our service but for our broader industry in general," Dorsey said. "It's added a lot more clarity around privacy and how data is being used to the people that we serve."

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