Twitter's stock falls below IPO price amid ongoing decline, concerns about user growth

Twitter's battered shares dipped below their IPO price on Thursday amid ongoing investor concerns about the company's ability to grow its user base.

Shares of the San Francisco-based short messaging service fell 5.8 percent to close at $26, after trading as low as $25.92 during the day. Twitter went public in November 2013 at an initial public offering price of $26 per share.

The stock is down more than 30 percent since Twitter's July 28 earnings report, when it warned that boosting its user growth rate will take a long time.

The challenge for Twitter is broadening the appeal of its service to the mass market amid fierce competition from Facebook as well as messaging apps like WhatsApp or Snapchat.