Twitter crashed on Tuesday (US time) for the second time in nine days when a software glitch stalled the popular messaging service for about one hour.
The company apologised to its 250 million users in a status blog, saying it had encountered "unexpected complications" during "a planned deploy in one of our core services."
The outage began around 11 am Pacific time and service had "fully recovered" by 11:47 am, the San Francisco-based company said. The stock rose as much as 3.7 percent before Twitter confirmed the glitch, but gave up most of the gains to end 0.25 percent higher.
The outage occurred just as Twitter co-founder Biz Stone took the stage in Austin, Texas, to speak at the South by Southwest Interactive festival, the annual gathering of tech enthusiasts that helped propel Twitter to national fame in 2007.
Twitter crashed briefly on March 2 during the Academy Awards, when the company's infrastructure was overwhelmed by a flood of tweets and retweets about a "selfie" featuring Oscar show host Ellen DeGeneres, Bradley Cooper, Jennifer Lawrence and many other celebrities.
Twitter, which was plagued by frequent outages during its early years, invested heavily in improving its site reliability before it went public in November 2013.