Nasdaq, Inc. is an American multinational financial services corporation that owns and operates (and is listed on) the NASDAQ (formerly National Association of Securities Dealers Automated Quotations) stock market and eight European stock exchanges, namely Armenian Stock Exchange, Copenhagen Stock Exchange, Helsinki Stock Exchange, Iceland Stock Exchange, Riga Stock Exchange, Stockholm Stock Exchange, Tallinn Stock Exchange, and NASDAQ OMX Vilnius. It is headquartered in New York City, and its president and chief executive officer is Adena Friedman.

Nasdaq, Inc. is the owner of the NASDAQ listing, founded in 1975.

In December 2005, the London Stock Exchange Group (LSE) rejected a £1.6 billion takeover offer from Macquarie Bank. The LSE described the offer as "derisory". It then received a bid in March 2006 for £2.4 billion from NASDAQ, which was also rejected by the LSE. NASDAQ later pulled its bid, and less than two weeks later on April 11, 2006, struck a deal with LSE's largest shareholder, Ameriprise Financial's Threadneedle Asset Management unit, to acquire all of that firm's stake, consisting of 35.4 million shares, at £11.75 per share. NASDAQ also purchased 2.69 million additional shares, resulting in a total stake of 15%. While the seller of those shares was undisclosed, it occurred simultaneously with a sale by Scottish Widows of 2.69 million shares. The move was seen as an effort to force LSE to negotiate either a partnership or eventual merger, as well as to block other suitors such as NYSE Euronext, owner of the New York Stock Exchange.

Subsequent purchases increased NASDAQ's stake to 29%, holding off competing bids for several months. However, only a further 0.4% of shareholders accepted the offer by the deadline and therefore the offer was rejected on February 10, 2007.

On October 2, 2007, NASDAQ purchased the Boston Stock Exchange. On November 7, NASDAQ announced an agreement to purchase the Philadelphia Stock Exchange.

On May 25, 2007, NASDAQ agreed to buy OMX, the Swedish-Finnish financial company that controls 7 Nordic and Baltic stock exchanges, for USD 3.7 billion to form NASDAQ OMX Group. As of February 27, 2008, the deal was completed.

On June 18, 2012, NASDAQ became a founding member of the United Nations Sustainable Stock Exchanges initiative on the eve of the United Nations Conference on Sustainable Development (Rio+20).

On December 12, 2012, NASDAQ OMX announced that it would acquire Thomson Reuters' investor relations, public relations and multimedia businesses for $390 million in cash. NASDAQ OMX completed the purchase on June 3, 2013.

In January 2013, NASDAQ OMX announced that it would combine its global data products and index businesses into a unit called Global Information Services, as part of an ongoing effort to broaden its portfolio.

On June 29, 2007, NASDAQ entered into an agreement to acquire DirectorsDesk.com, a management suite for Boards of Directors.

GlobeNewswire (previously PrimeNewswire) provides press release, editing and wire services. It was founded in 1998 and acquired by NASDAQ OMX in 2006.

On July 27, 2010, NASDAQ OMX Group, Inc. acquired SMARTS Group, the world-leading technology provider of market surveillance solutions to exchanges, regulators and brokers. SMARTS Group had been a private company operating out of Sydney, Australia, incorporating the market analysis software of Michael James Aitken. By 2017 SMARTS remained the leading market surveillance software, and was employed by thirteen regulators on forty-five exchanges.

NASDAQ OMX sold its stake in the Carpenter Moore D&O Insurance in 2009.