The top boss at the New York Stock Exchange breathed a sigh of relief at Twitter's glitch-free market debut—which he said may have helped get retail investors back into the market.
Twitter opened at $45.10 a share, a premium of more than 70 percent on its IPO price of $26 a share. The stock trades under the ticker symbol TWTR.
(Read more: Twitter's huge rally draws its share of skeptics)
"Good day for Twitter. Good day for the markets. Good day for everybody. We're pretty happy," said Duncan Niederaurer, the CEO of NYSE Euronext, on "Closing Bell."
The IPO not only went smoothly but volume exceeded his expectations of 100 million shares.
The NYSE made the unusual move of allowing a crowd to congregate on the trading floor to wait for a price. It was an effort to let retail investors "see it and watch it and feel like they were there," Niederaurer said.
"We wanted to bring everybody into the crowd. That was one of the objectives today," he said. "We wanted to do what Twitter does so well, which is really democratize everything. Make it accessible to everybody. We have nothing to hide—full transparency."
(Read more: Twitter honchos hit$4 billion jackpot)
It might have worked, too.
While institutional investors placed the pre-IPO bids, Niederaurer said retail investors stepped in as the stock went public and continued to be engaged throughout the trading session.
—By CNBC's Drew Sandholm. Follow him on Twitter @DrewSandholm.
