The San Francisco-based company said its average monetizable daily active users increased 20% year over year to 199 million, but analysts had expected that number to grow to 200 million.

Twitter shares fell as much as 8.5% after hours, after a 0.9% drop in the regular session to close at $65.09.

The microblogging company reported first-quarter net income of $68 million, or 8 cents a share, compared with a loss of $8.3 million, or 1 cent a share, in the year-ago period. Adjusted for stock-based compensation and other expenses, earnings were 16 cents a share. Revenue rose to $1.04 billion from $807.6 million in the year-ago quarter.

Analysts surveyed by FactSet had forecast adjusted earnings of 14 cents a share on revenue of $1.03 billion.

Twitter expects a second-quarter GAAP loss of $170 million to $120 million on revenue of $980 million to $1.08 billion. Analysts had forecast adjusted earnings of 16 cents a share and a GAAP loss of 4 cents a share on revenue of $1.06 billion.

Shares of Twitter have risen 20% year to date, and are up nearly 127% in the past 52 weeks. By comparison, the S&P 500 Index has increased about 12% so far this year, and is up nearly 45% in the past year.