The stock fell as much as 16 per cent after hours after gaining 8 per cent during the regular trading on Thursday.
The monetizable daily active users (mDAUs) were 187 million in the September quarter, falling shy of analysts' expectations of 195 million mDAUs. It still grew 29 per cent (year-over-year).
The Q3 revenue totaled $936 million, an increase of 14 per cent year over year while net income was $29 million.
Advertising revenue totaled $808 million, up 15 per cent year over year and total ad engagements increased 27 per cent year over year.
"We have grown our daily audience by 42 million in the last year as people all around the world come to Twitter to find out about the topics and events they care about most," Twitter CEO Jack Dorsey said on Thursday, who was grilled with Facebook CEO Mark Zuckerberg and Alphabet and Google CEO Sundar Pichai by the US Senate panel over Section 230 on Wednesday.
"I'm pleased mDAU grew 29 per cent year over year to 187 million, driven by global conversation around current events and product improvements," Dorsey added.
"As we look ahead to Q4, there is a lot to navigate — much of it unique to 2020," the company said.
"As we approach the US election, however, it is hard to predict how advertiser behaviour could change. The period surrounding the US election is somewhat uncertain, but we have no reason to believe that September's revenue trends can't continue, or even improve, outside of the election-related window," Twitter elaborated.
Advertisers significantly increased their investment on Twitter in Q3, engaging its larger audience around the return of events as well as increased and previously delayed product launches, driving revenue to $936 million, up 14 per cent year over year.
"We remain confident that our larger audience, coupled with ongoing revenue product improvements, new events and product launches, and the positive advertiser response to the choices we've made as we have grown the service, can drive great outcomes over time," said Ned Segal, Twitter's CFO.
Average US mDAU was 36 million and average international mDAU was 152 million for Q3.