In 2003, Duffy was appointed by President Bush and confirmed by the U.S. Senate as a member of the Federal Retirement Thrift Investment Board (FRTIB), a position he held until 2013.

[4][5] Duffy grew up on Chicago's southwest side in the Mount Greenwood neighborhood and graduated from Leo High School in 1976.

[1][8] While going to school, he worked nights at a bar called Chuck's in Lake Geneva, an affluent resort town popular with wealthy Chicagoans.

[1][9] There he met Vincent Schreiber, a Chicago Mercantile Exchange trader who convinced Duffy to take up a career in trading and eventually became his professional mentor.

[19] Duffy served as chairman of the combined company,[20] and is credited with leading the CME Group's acquisition of the New York Mercantile Exchange in 2008.

[22] In 2021 he negotiated a deal to move CME Group's technology to Google Cloud in order to increase access to the company's products.

[25][26] Duffy was appointed by President Bush and confirmed by the U.S. Senate in 2003 as a member of the Federal Retirement Thrift Investment Board (FRTIB), a position he held until 2013.

[5] Duffy said he suspected corruption at the cryptocurrency exchange on the day of his first one-on-one meeting with founder Sam Bankman-Fried, months before the historic FTX collapse.