The payment company, which has been spun off by eBay, will trade on the Nasdaq under the same ticker symbol it used more than a decade ago.
The online arts and crafts marketplace debuts on the Nasdaq stock exchange with shares trading at up to $35 per share.
The computer maker's founder and chief executive said the firm will continue to "aggressively execute" its long-term strategy in a deal valued at $24.9 billion.
Robo-Stox is a newly launched index that tracks robotics and automation companies, making it easier to invest in the industry.
Delivering a blow to the Nasdaq, which was accused of bungling Facebook's IPO, Twitter takes another route for its market debut.
The stock exchange went down around noon Eastern, but trading has finally resumed. Meanwhile, the S&P 500 continues to hold onto its gains.
The stock exchange argues that it cannot be sued via class-action suits because of its legal status as a self-regulatory organization.
Maybe Salesforce.com CEO Marc Benioff was right in saying that Facebook should have gone public on the New York Stock Exchange.
The Securities and Exchange Commission said the stock exchange operator can provide cash compensation to investors who lost money while attempting to trade Facebook shares during its IPO.
U.S. regulators are rumored to be discussing a settlement with the stock exchange over an investigation into technical glitches that cost investors millions on the first day of trading.