John Koudounis

John Koudounis, President and CEO of Calamos Investments, spearheads strategic initiatives and drives innovative business solutions for the firm. Under his leadership, AUM has nearly tripled to $48 billion, and Calamos has moved into: active ETFs, private credit, and digital assets –launching the world's first protected Bitcoin ETFs. Appointed as CEO in 2016 by Founder John P. Calamos, Sr., Koudounis brings over 35 years of financial services experience. He previously served as President and CEO of Mizuho Securities USA, Inc. building the firm into a full-service investment bank, expanding its debt and equity capital markets teams. Prior to that, he was Managing Director and Head of Fixed Income at ABN AMRO Americas. A sought-after thought leader, Koudounis speaks at global conferences and with media outlets like CNBC, Fox Business and Bloomberg TV. Beyond his executive career, he demonstrates a strong commitment to philanthropy.

In 2020, he founded the Chicago CEO COVID-19 Coalition. Koudounis is a member of the Leadership Council at Concordia and holds various board roles with World Business Chicago, the National Hellenic Museum, and The Hellenic Initiative, a King’s Trust International patron, and an executive advisory board member for the SEAL Future Foundation. He is an Archon of the Ecumenical Patriarchate, a Leadership 100 member, and Chairman of the Ecumenical Patriarch Bartholomew Foundation. Koudounis graduated from Brown University with a degree in International Diplomacy & Foreign Affairs and Economics.