
Greg operates at the intersection of strategy and domain know-how. His proven process for scaling and exiting boutique professional services firms is the cornerstone of value that Capital 54 provides to its investments. Greg is passionate about creating financial independence for all.
Prior to opening the family office, Greg had two careers spanning 25 years. He co-founded SBI, a professional service firm, and served as CEO for 11 years. After scaling the firm, he successfully exited in 2017 by selling his interest. Prior to SBI, Greg was an executive at EMC Corporation, a leader in the data storage industry.
He is a published author and his podcast and Company TV series on Sales and Marketing insights from B2B thought leaders and growth experts, set an industry benchmark. Greg is an active member of YPO and several private peer organizations including being the founder of Collective 54.

As an entrepreneur, investor and the founder of Saxum, an award-winning integrated marketing and communications agency headquartered in Oklahoma City, Renzi Stone brings to Capital 54 two decades of expertise in reputation and issues management, marketing and branding strategy, succession planning, crisis communication, and public affairs for professional services firms, energy companies, large foundations, healthcare entities and financial services organizations.
Prior to founding Saxum in 2003, Stone worked for ESPN where he did color commentary for college basketball games and served as Vice President of a national public affairs agency headquartered in Washington, D.C., where he specialized in quantitative and qualitative public opinion research. He’s also an accomplished speaker and editorial contributor who’s been featured and quoted in PRWeek, Advertising Age, The New York Times and on CNBC.
A determined leader in the marketing and public relations fields, Stone has served as President of the Americas for IPREX and on the board of directors for the PR Council in New York. In 2015, he was appointed by then-Oklahoma Governor Mary Fallin to the University of Oklahoma Board of Regents where he served until 2019. He’s also served as a director for the global organization, YPO. In Oklahoma, Stone is on the board of the Oklahoma Hall of Fame and is the former Chairman of the Board of Oklahoma City’s united arts fund, Allied Arts.
Stone attended and played basketball at the University of Oklahoma (1996-2000) where he was named a Big 12 Conference Medal Winner—an honor awarded to the conference’s top senior athlete. A Rhodes Scholar finalist while at Oklahoma, he received a bachelor’s degree in history. He is currently working towards an Executive MBA at Harvard Business School through YPO. Renzi and his wife Lee Anne live in Oklahoma City with their two boys, Jackson and Walker.