Pennington Partners & Co. Expands to the Southeast with Addition of Keith Kellum and Marilyn Santiago

BETHESDA, Md., Sept. 3, 2025 /PRNewswire/ -- Pennington Partners & Co., an award-winning multi-family office serving entrepreneurial families, high income earners, and multi-generational families with integrated wealth and investment solutions, today announced the addition of Keith Kellum and Marilyn Santiago as Partners. These appointments underscore Pennington's continued commitment to building a best-in-class team dedicated to elevating the lives of the families we serve.

Santiago joins Pennington as a Partner and Head of Relationship Management, bringing more than two decades of experience leading client relationships at BNY. Over her 23-year tenure, she played a central role in developing the firm's client service framework while overseeing some of its largest and most complex families. She is widely recognized for her ability to foster deep, lasting relationships and to navigate the unique needs of ultra-high-net-worth clients.

Kellum joins as a Partner and Portfolio Manager, with deep expertise advising some of the country's most prominent families, which include first-generation entrepreneurs as well as multi-generational dynasties. Most recently, he built and led the Virtual Family Office practice nationally at BNY Wealth, where he developed platforms and scaled advisory services for families of significant wealth. He brings extensive experience in active wealth management, integrating investment strategy, estate planning, and family governance to help clients achieve lasting impact.

"Keith and Marilyn are outstanding leaders whose experience and values align directly with our mission of bringing a client-first approach to the families we serve," said Brian Gaister, Co-Founder and CEO of Pennington Partners. "Having them on board enhances our ability to deliver the comprehensive and thoughtful solutions families need in today's complex environment. We are thrilled to welcome them to the team."

For Santiago, the move represents a continuation of her lifelong focus on client service. "Pennington is deeply committed to building trusted relationships and elevating the client experience, values that have guided me throughout my career," she added. "I'm excited to join this team and help families navigate complexity with confidence."

"Families whose wealth continues to grow despite spending, taxes, and inflation face a level of complexity that demands more than traditional advice," said Kellum. "Pennington delivers its expertise with clarity through a platform that simplifies wealth planning while helping families learn from each other. I look forward to working with clients to steward what they've built and shape legacies that last."

With Santiago and Kellum's arrival, Pennington further strengthens its position as a trusted partner for wealthy families, offering integrated solutions across investment management, income and estate planning, governance, wellness, and family office services.

About Pennington Partners & Co.
Originally founded to serve the needs of its two founding families — entrepreneurs who built and sold businesses in various industries — Pennington Partners is dedicated to elevating the lives of successful entrepreneurial founders and their families. With over $4 billion in assets under advisement, Pennington offers a comprehensive suite of investment, wealth planning, and financial administration services tailored to founders, CEOs, wealth creators, and multi-generational families. To learn more, visit www.penningtonpartners.co.

Media Contact:
Ryan Walker
R.J. Walker & Co.
[email protected]

SOURCE Pennington Partners & Co.