Twitter CEO Jack Dorsey. Bill Pugliano/Getty Twitter shares have hit an all-time low.

In early trading on Tuesday the stock fell 3% to as low as $13.90 a share, a level it had not reached since the company went public in November 2013. The broader stock market was also selling off.

The social network has been struggling to ramp up its number of active users.

When it reported first-quarter earnings last week, its revenues missed estimates and guidance for the second quarter was also light.

Twitter said brand advertising was weaker than it had expected in the first quarter. Some of the analyst commentary noted concern that Twitter was losing ad-revenue share to competitors like Facebook, Instagram, and Snapchat.

Several Wall Street analysts that cover the stock downgraded their outlook for future earnings and their expectations for how high the shares can climb.

Twitter shares have plunged 39% this year. They are down 66% from the initial public offering late in 2013.

Here's a chart showing the lifetime of Twitter's stock: