Wednesday, 5 February 2014
The loss was expected by analysts, who highlighted Twitter's revenues, which rose 110% last year to reach $665m.
But a reported slow growth in user numbers was a bigger concern for investors.
Twitter averaged 241 million monthly users in the last quarter of the year, up just 3.8% on the previous quarter.
That represents a slowdown compared with a growth rate of 10% seen at the beginning of 2013.
Timeline views were down nearly 7%, suggesting users were refreshing their feeds less often.
"What this report will do is it will question how mainstream is Twitter as a platform," said Arvind Bhatia, an analyst at Sterne, Agee & Leach.
Shares fell as much as 12% in after-hours trading on Wednesday.
Nate Elliott, an analyst at research firm Forrester, told AFP: "If you don't have an engaged user base, you don't have a business. They have got to do better on users, that is the entire story."
