[4] OM AB (Optionsmäklarna) was a futures exchange founded by Olof Stenhammar in the 1980s to introduce trading in standardized option contracts in Sweden.

[6] During the dot-com bubble in the early 21st century, OM, together with investment bank Morgan Stanley Dean Witter, launched a virtual European stock exchange called Jiway.

[11] On September 19, 2006, the Iceland Stock Exchange owner Eignarhaldsfelagid Verdbrefathing (EV) announced it would be acquired by OMX in a deal valuing the company at 250 million SEK.

The acquisition greatly expanded its product offerings and made its client list the largest of all trading system technology providers.

In December 2005, the London Stock Exchange Group (LSE) rejected a £1.6 billion takeover offer from Macquarie Bank.

[20] 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.

[29] On December 12, 2012, NASDAQ OMX announced that it would acquire parts of Thomson Reuters for $390 million in cash.

[32] During Christmas of 2018, shareholders representing 25% of Oslo Børs VPS Holding (the Norwegian Stock Exchange and national CSD operator)[33] held a private auction of share sale.

Nasdaq did not participate in the auction due to the hostile nature of the bid (held without Oslo Børs boards knowledge or approval).

Following this, Nasdaq acquired 32.5% shares in open market (mainly from individual shareholders/employees),[34] and submitted an official bid, with unanimous recommendations from board and some key shareholders,[35] to acquire remaining shares for 152 NOK, and later increased offer to 158 NOK (or almost 44% premium of December 17, 2018 closing price, to match Euronext offer),[36] additionally making the case to Norway's markets regulator that in cases like this, 2/3 of the share control may be necessary to comply with any applicable regulatory requirement.

[38] In June 2023, Nasdaq announced that it had agreed to acquire Adenza from Thoma Bravo in a $10.5 billion cash-and-stock deal, the biggest for the US exchange operator to date.

[45] SMARTS Group had been a private company operating in Sydney, Australia, incorporating the market analysis software of Michael James Aitken.

[46][47] By 2017 SMARTS remained the leading market surveillance software,[48] and was employed by thirteen regulators on forty-five exchanges.

The following exchanges are operated by Nasdaq, Inc.:[50] The company's stock market activities are categorized into three divisions: In North America, OMX supports its most high-profile customers such as the Financial Industry Regulatory Authority (FINRA), ICAP, ISE, and IDCG, which are powered by OMX trading systems such as X-stream, CLICK, CONDICO and SAXESS.