Twitter shares plunged in early trading as the social-media service reported weak user numbers, a day after Facebook suffered the biggest one-day loss in USA market history.
Twitter reported a revenue of $711 million, up 24 percent year over year.
Twitter has warned investors that new investments in security and safety will impact user metrics.
Earlier this year Twitter admitted that more than 50,000 Russia-linked accounts used its service to post automated material about the 2016 USA election.
Twitter reiterated Friday that it is trying "to invest in improving the health of the public conversation" on its platform, making the "long-term health" of its service a priority over short-term metrics such as user numbers.
Twitter's aggressive moves to clean up the platform has not detracted from its advertising revenue, said the social network's chief financial officer Ned Segal during a conference call. "This is important work that complements what we're doing to connect people with interest and help them discover information".
Its size is only about a seventh of the more than 2.5 billion Facebook counts across its website, the WhatsApp messaging service and the Instagram photo-sharing app. Google parent company Alphabet, however, is having a strong week after reported earnings on Monday.
Twitter (TWTR) traded -18% lower on Friday morning, after posting earnings that beat analyst estimates.More news: With A.L. East title slipping away, Yankees trade for J.A
The company has recently announced a crackdown, by deleting.
Twitter's second-quarter net income rose to $100.1 million, compared with a loss a year ago during the same period.
Twitter shares plunged up to 20% in premarket trading after the social media platform said monthly active users had fallen by one million.
Twitter shares were up 79% year-to-date through Thursday. Markets outside the U.S. grew 44% year on year to $344 million. In Q3, however, they removed what were determined to be "fake accounts", which will be reflected in their next earnings report. The Associated Press also found that Twitter suspended 56 million such accounts in the last quarter of 2017.
Twitter has focused on safeguarding the service in recent months amid scrutiny of its role in spreading fake news and election meddling as well as the broader data privacy backlash hitting the tech industry.
"The problem was bad, and it did go on for way too long". The company said the posts had reached at least 677,000 Americans.
Snap is under pressure Friday following a rough few days for social-media companies.
The president appeared to seize on a Vice report that said that the accounts of some conservatives did not show up in auto-populated search suggestions when people typed in their names. Technology improvements have resulted in removing twice the number of accounts that violate Twitter's spam policies.