CSOSS 2025
Sessions & Speakers
Featured Speakers
John Koudounis joined Calamos Investments as Chief Executive Officer in 2016. He became the firm’s first designated CEO hired by Founder John Calamos, Sr., as part of Calamos’s succession plan. Serving as a driving force behind improving strategic initiatives, Mr. Koudounis plays a critical role in delivering innovative solutions to business development and expanding product breadth for the firm’s global base of clients. Under his leadership, firm profitability and AUM growth have increased substantially.
Mr. Koudounis has over 35 years of experience in financial services, including executive leadership in the global securities business and a deep background in global capital markets. Most recently, he served as
President and Chief Executive Officer of Mizuho Securities USA, Inc. (MSUSA), a subsidiary of Mizuho
Financial Group, one of the world’s largest full-service financial institutions. During his tenure at Mizuho
Securities, he built the firm into a full-service investment bank, expanding its debt and equity capital
markets teams. Because of his leadership, the firm also grew in profitability, number of clients, and
product diversification, allowing Mizuho to be considered globally as a top-tier investment bank. Before
joining MSUSA in 2008, he was Managing Director and Head of Fixed Income for ABN AMRO Americas,
where he played a critical role in that firm’s successful growth.
Charmel Maynard, Strategic Partnerships & Impact, General Catalyst
Prior to General Catalyst, Charmel served as the Chief Investment Officer & Treasurer for the University of Miami. He led the University’s efforts to invest over $4B in assets, including endowment and pension funds. Mr. Maynard was also responsible for the University’s ~$2B capital structure, including liquidity and debt issuances. Additionally, he managed treasury and cash management. Mr. Maynard was previously a vice president with J.P. Morgan’s Investment Bank in New York City. During his 10-year career with J.P. Morgan, he focused on investment banking debt capital markets and leveraged finance, where he advised clients on capital structure solutions, deal structuring, and execution of syndicated revolving credit facilities, institutional term loans, and bond issuances.
He most recently served on the Sculptor Capital Management Board of Directors (NYSE: SCU) until the
recent sale of the Company (Member of Special Committee formed to explore potential interest from
third parties, Audit Committee, Nominating Committee, Corporate Governance and Conflicts
Committee). He currently serves on the New World Symphony Board and the Mead Art Museum Board as the
chair of the Budget Committee, JPB Foundation Investment Committee, Catalyst Miami Board of
Directors (Chair of Finance Committee), Knight Foundation Community Advisory Board, and Black Angels
Miami Board.
Roger McClendon, Executive Director, Green Sports Alliance
Roger McClendon is the Executive Director of the Green Sports Alliance. In his role, he leads the Alliance of international sports and stadium executives, as well as sustainability experts, to use sports as a vehicle to promote healthy, sustainable communities throughout the world.
Before joining the Alliance, Roger was the first-ever Chief Sustainability Officer for Yum! Brands, whose
holdings include Taco Bell, Pizza Hut, and KFC restaurants. He also led the development of Blueline, a
sustainable design guide for restaurants built on the LEED certification program. Blueline was a global
standard implemented in approximately 5,000 Yum! Brand restaurants globally. Due to his efforts, Yum!
Was named to the Dow Jones Sustainability Index in 2017 and 2018, as well as one of the 100 Best
Corporate Citizens by Corporate Responsibility Magazine.
Roger’s other passion is basketball. He was named a McDonald’s All-American in 1984, one of the top 25
high school basketball players in the nation and went on to be a four-year starter who closed his
University of Cincinnati men’s basketball career as the No. 2 scorer, second only to Oscar Robertson at
the time. Roger was inducted into the UC Athletics Hall of Fame in 1998. He holds a Bachelor of Science
in Computer & Electrical Engineering from the University of Cincinnati.
Beth Williamson, Vice President, Head of Sustainable Equity Research and Associate Portfolio Manager, Calamos
Beth Williamson joined Calamos Investments in 2021 and contributes 20 years of ESG
investment experience. Before joining Calamos, Beth worked at Trillium Asset Management, rising to the position of Director of ESG with responsibilities for developing and implementing ESG research methodologies and overseeing corporate engagement efforts and the firm’s ESG materiality framework. Previously, she was a Sustainability Analyst for Portfolio 21 Investments.
She began her career as a Shareholder Advocate at Green Century Capital Management. Beth
earned a B.S. degree in Environmental Science from the University of Vermont and an M.S. degree
in Sustainable International Development from Brandeis University.