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.
CEO Tim Cook delivers on a promise to move into a new product category, making a foray into wearable devices with the Apple Watch. Plus: Bigger-screen iPhones and a mobile service called Apple Pay.
Maybe Salesforce.com CEO Marc Benioff was right in saying that Facebook should have gone public on the New York Stock Exchange.
BlackBerry's acquisition of German software firm Secusmart aims to secure voice and data and put better mobile security in every president and chancellor's hand.
Marty Beard will start as chief operating officer immediately and will be responsible for "cross-functional organizations" at the company.
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.