On October 24, 2017, it received regulatory approval from the U.S. Securities and Exchange Commission (SEC) to list companies.

[3] In September 2019, IEX announced that its co-founder and COO, John Schwall, would retire from the company by the end of 2019.

[4] The genesis and early days of the exchange are chronicled in the 2014 book Flash Boys: A Wall Street Revolt by Michael Lewis.

[7] This method was subsequently implemented by competing stock exchange NYSE American in response to the SEC approval of IEX.

[6][8][9] In 2020, Caisse de dépôt et placement du Québec made a strategic investment in IEX Group.

[12] After a 13-month wait, on October 24, 2017, IEX Group Inc. received regulatory approval from the SEC to list companies.

[18] IEX delays the flow of data from the exchange and ensures that it arrives simultaneously at two points of presence in New Jersey.

Traders are not allowed to co-locate equipment adjacent to IEX's own servers, unlike many other trading platforms.

Katsuyama argues that this arrangement advantages regular investors contrarily to high frequency trading (HFT) firms, by preventing, for instance, HFT firms from jumping to the top of the order queue and front running normal investors.

[23] IEX also offers an API service, allowing developers to query US and Canadian stock data.