Duffy has been Executive Chairman of CME since 2007 and Executive Chairman and President since 2012.He has served as Chairman of the Board of Directors of CME and CME Holdings since April 2002 and as Executive Chairman since October 2006. Duffy has served as Vice Chairman of the Board of Directors of CME Holdings since its inception in August 2001 and was Vice Chairman of the Board of Directors of CME from 1998 to April 2002.Duffy was President of TDA Trading, Inc. from 1981 to 2002.Duffy has been a member of CME since 1981 Duffy has been a member of CME since 1981 and a member of CME's Board of Directors since 1995.

From 2003 to 2013, Duffy served as a member of the Federal Retirement Thrift Investment Board (FRTIB), appointed by President George W. Bush and confirmed by the U.S. Senate, to administer the Thrift Savings Plan, a tax-deferred pension plan designed for U.S. federal government employees. Plan, a tax-deferred pension plan designed for U.S. federal government employees.)

During his tenure, Duffy led the first merger transaction in the futures industry, when the Chicago Board of Trade merged with the Chicago Mercantile Exchange to form the Chicago Mercantile Exchange in 2007. The following year, he led the acquisition of the New York Mercantile Exchange (NYMEX), merging the global benchmark energy trading platform into CHME.In 2018, he led CHME's acquisition of NEX, streamlining the trading process for futures, options, spot, and over-the-counter (OTC) markets.In 2021, Duffy partnered with Google Cloud ( Google Cloud) in a landmark partnership to provide broader access, more new products, and more efficient services to the derivatives market through the cloud.

Under his leadership, the Exchange has received widespread industry recognition and numerous awards for exchange, clearinghouse and product innovation. For eight consecutive years, the Exchange has been recognized as the Most Valuable Exchange Brand, and Duffy was named CEO of the Year at the 2018 Futures & Options World (FOW) International Awards. He also currently serves as co-chair of the Mayo Clinic's Greater Chicago Leadership Council and as vice chair of the Chicagoland Stock Exchange Foundation.

He attended the University of Wisconsin-Whitewater, where he received an honorary Doctor of Public Service degree from Saint Xavier University in 2019 and a Doctor of Humane Letters degree from DePaul University in 2007. (DePaul University) in 2007.