[4] On May 15, 1882, the Chicago Stock Exchange officially became public and opened its offices, with Henrotin being the first to promote it along with some business associates.

[4] In 1894, the Chicago Stock Exchange moved its trading floor to the old Chicago Stock Exchange building, designed by the firm of Adler & Sullivan, which was located at corner of Washington and LaSalle streets.

[5] The exchange began to flourish significantly in the late 1880s, with the rate of transactions of stocks and bonds increasing and earning them big profits.

[6] In October 1915, the basis of quoting and trading in stocks changed from percent to par value to dollars.

In 2005, the SEC approved a change of the ownership structure of the CHX from a not-for-profit, member-owned company to a for-profit, public stockholder-owned corporation (demutualization).

In 2006, the Exchange announced regulatory and shareholder approval of an investment in CHX by Bank of America Corporation, Bear Stearns (acquired by JP Morgan Chase in 2008), E*TRADE FINANCIAL Corporation, and Goldman, Sachs & Co.

A minority ownership position is held by Bank of America, E-Trade, Goldman Sachs and JPMorgan Chase.

[16] Moreover, Congressman Robert Pittenger urged the United States Department of the Treasury to look into the Casin Group's background.

[19] In 2016, CHX rolled out its on-demand auction product, CHX SNAP[20] (Sub-second Non-displayed Auction Process), which received regulatory approval[21] from the Securities and Exchange Commission in October 2015 and a thorough review from the Federal Reserve Bank of Chicago.