Founded in 1790 as the "Board of Brokers," it was located at the Merchants Coffee House, now known as the City Tavern, at the corner of Second and Walnut Streets.

[8] In 1831, Stephen Girard’s Bank had formed the "Philadelphia Merchant’s Exchange Company" to erect a new building to house the Board of Brokers and other groups.

The 1700 block of Ionic Street, a narrow thoroughfare just north of this building, was renamed Stock Exchange Place and was still signed as such as of 2017.

[citation needed] In December 1968, in response to a fiscal crisis, Philadelphia imposed a $0.05 per share stock transfer tax for all transactions on the PHLX.

In February, a court ruled that the tax was illegal, and the PHLX moved its trading floor back to its headquarters in the city.

These firms—Morgan Stanley, Citigroup, Credit Suisse First Boston, UBS, Merrill Lynch and Citadel LLC—collectively owned about 89% of the exchange.

On October 20, 2007, The Wall Street Journal reported that the exchange was for sale by a group of its shareholders, and was expected to be sold for about $600 million.

[14] On November 7, 2007, NASDAQ announced a "definitive agreement" to purchase PHLX for $652 million, with the transaction expected to close in early 2008.

[2] On July 24, 2008, the acquisition was completed, creating the third-largest options market in the U.S. On October 29, 2012, the stock exchange was shut down for two days due to Hurricane Sandy.