Trading on the New York Stock Exchange under the symbol "TWTR," shares opened at $45.10, 73 percent above their initial offering price.
In the first few hours, the stock jumped as high as $50.09. At midday, it was up 73.6 percent, at $45.14, amid a broader market decline.
The narrow price range indicated that people felt it was "pretty fairly priced," said JJ Kinahan, chief strategist at TD Ameritrade.
The immediate price spike "clearly shows that demand exceeds the supply of shares," said Wedbush analyst Michael Pachter.
Earlier in the day, Twitter gave a few users rather than executives the opportunity to ring the NYSE's opening bell. The users included actor Patrick Stewart, who played Captain Jean-Luc Picard in "Star Trek: The Next Generation"; Vivienne Harr, a 9-year-old girl who ran a lemonade stand for a year to raise money to end child slavery; and Cheryl Fiandaca of the Boston Police Department.
Twitter raised $1.8 billion Wednesday night when it sold 70 million shares to select investors for $26 each. Had it priced the stock at $30, for instance, the company would have taken away $2.1 billion. At $35, it would have reaped nearly $2.5 billion.
"In hindsight, when you look at this, you almost think they left a little too much money on the table," Entner said.
At $26 per share, Twitter was valued at more than $18 billion based on its outstanding stock, options and restricted stock expected to be available after the IPO. That was less than a quarter of Facebook's $104 billion value at the time of its IPO.
Named after the sound of a chirping bird, Twitter's origins date back to 2005, when creators Noah Glass and Evan Williams were trying to get people to sign up for Odeo, a podcasting service they created. Odeo didn't make it.
By early 2006, Glass and fellow Odeo programmer Jack Dorsey began work on a new project: teaming with co-worker Christopher "Biz" Stone on a way to corral text messages typically sent over a phone.
It was Glass who came up with the original name Twttr. The two vowels were added later. The first tweets were sent on March 21, 2006.
By 2007, Twitter was incorporated with Dorsey as the original CEO and Williams as chairman. Dorsey and Williams would eventually swap roles. Both remain major shareholders, though neither runs the company. Glass, meanwhile, was effectively erased from Twitter's history, writes New York Times reporter Nick Bilton in "Hatching Twitter: A true story of money, power, friendship, and betrayal."
Since those early days, the site has attracted world leaders, religious icons and celebrities, along with CEOs, businesses and countless marketers and self-promoters.
The company tried to avoid the trouble that plagued Facebook's high-profile debut, which was marred by technical glitches. As a result, the Securities and Exchange Commission fined Nasdaq $10 million, the largest ever levied against an exchange.
The clumsy debut had lasting consequences for Facebook, which closed just 23 cents above its $38 IPO price on that first day and later fell much lower. The stock needed more than a year to climb back above $38.