Roszell Mack III, Chief Executive Officer and Managing Member, founded Mack & Co., LLC, the holding company for all Mack & Co. related affiliates, entities and subsidiaries in 2010. He is also the Chief Executive Officer and Managing Partner of Mack & Co. Partners, LP, a Dallas-Texas based SEC Registered Investment Adviser.

Prior to founding Mack & Co., LLC, he was co-founder of Ascend Venture Group, LLC, a New York-based venture capital firm. Prior to Ascend, Mr. Mack was an investment banker with Goldman Sachs & Co. and Salomon Smith Barney, where he facilitated the origination, structuring and execution of mergers and acquisitions, and executed capital raising and private placement transactions for a global base of family office and institutional clients.

Mr. Mack graduated from Yale University and earned an MBA from Harvard Business School. He serves on the board of directors of Sanara MedTech Inc. (NASDAQ: SMTI) and is a member of the board of trustees of The Edwin Gould Foundation. He is a former board of trustees’ member of the Vanderbilt-Ingram Cancer Center in Nashville, TN.

Preston DeLong is a Vice President at Mack & Co. Partners, LP where he focuses on sourcing, evaluating, and executing late-stage venture and growth equity investments for the firm’s Direct Investment business. He leads due diligence and underwriting efforts, and works closely with founders, management teams, and co-investors throughout the investment process.

Prior to joining Mack & Co., Mr. DeLong was an investor at Crow Holdings, where he focused on investments across PropTech, FinTech, and AI/data infrastructure. He led diligence and underwriting processes, developed investment theses, and supported portfolio company initiatives. He began his tenure at Crow Holdings in asset management, where he built data and analytics platforms to enhance investment decision-making and operational performance.

Earlier in his career, Mr. DeLong held roles in strategy and business operations at JPMorgan and in management consulting at KPMG, advising Fortune 500 clients on M&A, technology strategy, and operational transformation.

Mr. DeLong earned a Bachelor of Business Administration in Management Information Systems from Harding University.

Charles Hornat, Chief Technology Officer and Chief Information Security Officer, joined Mack & Co. Partners, LP in 2023. With more than 25 years of information security experience, Charles is an information security professional specializing in helping organizations strike the right balance between business needs and the risks and costs of controls.

He has a proven track record of developing information security strategies in technically demanding global environments for giants of industry such as Standard and Poor’s and Sony, among others.

Eleanor Jeffus, Special Projects and Administrative Associate, joined Mack & Co. Partners, LP in 2025. In her role, she provides strategic and operational support across a range of initiatives, including project coordination, administrative management, and investor communications. Prior to joining Mack & Co., she gained experience in both criminal and family law practices, supporting attorneys in case management and client services.

Ms. Jeffus earned her undergraduate degree from Texas A&M University, where she majored in Society, Ethics, and Pre-Law, with minors in Philosophy and Leadership.

Maximiliana Windisch-Graetz, Financial Analyst, joined Mack & Co. Partners, LP in 2026. In her role, she works as a generalist across all four Mack & Co. business verticals providing analytical and execution support across a range of business initiatives and working with Mack & Co.’s global family office clients.

Ms. Windisch-Graetz earned her undergraduate degree with High Distinction from SMU University, where she majored in Business Administration and Real Estate Finance and was Captain of the Tennis Team and Co-Captain of the Basketball Team.

Richard Zack is the CEO and Managing Member of M&CO. Securities LLC, Mack & Co.’s wholly-owned FINRA registered broker-dealer. Mr. Zack also serves as the Chief Compliance Officer and General Counsel of Mack & Co. Partners, LP. He joined Mack & Co. Partners, LP in 2024. Before his current position, he occupied similar roles at Bleakley Financial, Group, a $9 billion RIA, and Wainwright Investment Counsel, a $5 billion RIA. Mr. Zack is also a FINRA arbitrator and has served as a Branch Chief at the U.S. Securities and Exchange Commission in Washington, D.C. With extensive experience in capital markets, legal matters, and compliance risk management, he has also held executive leadership positions at various financial institutions, including the National Bank of Canada and Bank of America.

Mr. Zack earned his Master of Laws in Taxation from Georgetown University Law Center, a Juris Doctorate from Rutgers University Law School, and his undergraduate degree from Emory University.