Twitter sees fewer users than expected and stock sinks (Video)

Shares of Twitter have risen 20% year to date

Twitter Inc. on Thursday reported increased quarterly revenue on the strength of ad sales, but its user numbers fell short of expectations.

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.