About
A Career in Investing, Private Credit,
and Permanent Capital Vehicles
Leonard “Len” M. Tannenbaum, CFA, is an investor and entrepreneur with over three decades of experience in private credit, alternative investments, and permanent capital vehicles.
A pioneer in the Business Development Company (BDC) industry, Len founded Fifth Street in 1998 and built it into a national alternative credit platform providing capital to middle-market companies. Following the transition of Fifth Street’s publicly traded funds to Oaktree Capital Management in 2017, Len shifted his focus to investing through his family office and, ultimately, the development of Tannenbaum Capital Group.
Throughout his career, Len has invested across private credit, BDCs, and real estate lending, with experience spanning both public and private investment vehicles.
Len was raised on Long Island, New York, in a family that helped shape his early appreciation for hard work, independence, and entrepreneurship. His mother immigrated to the United States from Cuba, while his father was an attorney and managing partner of a law firm.
Those influences helped foster Len’s interest in business and building companies from an early age. Throughout his career, he has viewed entrepreneurship not only as a professional pursuit, but also as an opportunity to pass along practical lessons about judgment, responsibility, and the value of creating something enduring to the next generation.
Len attended the Wharton School of the University of Pennsylvania, earning a B.S. in Economics in 1993 and an MBA in Finance in 1994 through Wharton’s submatriculation program. He later earned the Chartered Financial Analyst (CFA) designation.
Early Investment Experience
Following Wharton, Len began his career as an equity analyst in Merrill Lynch’s small-company group, developing an early expertise in evaluating emerging and middle-market businesses.
He went on to hold investment roles at Pilgrim Baxter and LAR Management, broadening his experience across public equities and a range of market environments. Over time, his investment focus increasingly shifted toward credit-oriented strategies, including structured equity, mezzanine and convertible debt, where disciplined underwriting, contractual cash flows, and downside protection played a greater role in the investment thesis.
This evolution—from analyzing companies as an equity investor to structuring capital as a credit investor—helped shape Len’s investment philosophy and laid the foundation for the business he would establish in 1998.
Building Fifth Street
In 1998, at just 27 years old, Len founded the private investment business that would ultimately become Fifth Street.
Initially focused on providing flexible capital to small and middle-market companies, Fifth Street expanded its lending capabilities, geographic reach, and investment strategies as the business grew. Under Len’s leadership, it evolved into a national alternative credit platform managing both private funds and publicly traded investment vehicles, including two Business Development Companies (BDCs).
As Founder and CEO, Len’s role extended well beyond investing. He built and led the organization, recruited investment professionals, raised institutional and public capital, developed the firm’s credit and underwriting platform, and worked closely with boards, shareholders, and other stakeholders while navigating multiple economic and credit cycles.
At its peak, Fifth Street managed over $5 billion in assets across its private and publicly traded investment vehicles, establishing Len as an early leader in the growth of the BDC and private credit markets.
Experience With
Publicly Traded Companies
A significant chapter of Len’s career involved building investment businesses and accessing the public capital markets, including taking companies public on both the NYSE and NASDAQ.
Fifth Street Finance Corp. became a publicly traded Business Development Company (BDC) focused on providing capital to small and middle-market businesses. Fifth Street subsequently expanded its platform with additional public and private investment vehicles designed to serve different segments of the credit markets.
Across these businesses, Len held senior executive and board positions with responsibility spanning investment strategy and oversight, capital formation, public-company governance, shareholder communications, and the management of credit portfolios through multiple market cycles.
These experiences shaped Len’s perspective on permanent capital and the evolution of the BDC structure, as well as the importance of investor alignment, disciplined governance, and the responsibilities that come with managing publicly traded investment vehicles.
The Transition
In 2017, Fifth Street entered a major transition.
Oaktree Capital Management assumed the investment-management agreements of Fifth Street Finance Corp. and Fifth Street Senior Floating Rate Corp., the two publicly traded business development companies previously managed by Fifth Street. The companies were subsequently renamed Oaktree Specialty Lending Corporation and Oaktree Strategic Income Corporation.
The transaction concluded Len’s leadership of the Fifth Street platform and marked the end of a business he had spent nearly two decades building.
Following the transition, Len stepped away from institutional asset management for a period and concentrated on managing family capital, evaluating investments, and considering what he wanted to build next.
Returning to His Roots
Following Fifth Street, Len shifted his focus to investing family capital across a broad range of strategies and opportunities.
Operating through his family office gave Len a different perspective on investing—one shaped by allocating his own capital as a principal and long-term owner. It provided the flexibility to pursue opportunities across markets, partner with experienced management teams, and deploy patient capital where he believed experience, alignment, and disciplined investing could create enduring value.
During the COVID-19 period, Len began building a new investment organization alongside his wife, Robyn, members of his family, and a team of experienced investment professionals.
That effort ultimately became Tannenbaum Capital Group (TCG), bringing together the perspective of a family office with the investment experience and institutional discipline developed over Len’s career.
Tannenbaum
Capital Group
Len is the Founder of Tannenbaum Capital Group (TCG), an investment platform that brings together affiliated asset managers specializing in credit-oriented strategies, including private credit, opportunistic credit, and real estate lending.
TCG represents the next evolution of Len’s career—combining nearly three decades of experience investing in credit and building financial businesses with a model designed to support specialized investment teams and align capital with experienced management.
The organization also reflects Len’s commitment to building a multigenerational family enterprise. Together with his wife, Robyn, and their children, Len has used the development of TCG as an opportunity to share the lessons of entrepreneurship, investing, decision-making, and stewardship that have shaped his own career.
Today, Len helps guide TCG’s overall strategic direction while experienced executives lead its individual investment businesses. The platform emphasizes disciplined underwriting, specialized investment expertise, and meaningful alignment of capital between its principals and investors.
Continuing Involvement With Wharton
Len has maintained a longstanding relationship with the Wharton School as an alumnus, advisor, contributor, and active participant in the school’s community.
His involvement has included service on the Wharton Graduate Executive Board, support for educational and research initiatives, and contributions to Wharton publications on investing, entrepreneurship, family enterprise, and wealth management.
In a 2025 Wharton Magazine interview, Len reflected on his experience building Fifth Street and the evolution of TCG as a family enterprise. He continued that engagement in 2026, contributing his perspective on consolidation, culture, and client relationships within the evolving wealth-management industry.
Through his ongoing involvement with Wharton, Len has sought to share lessons from over three decades of investing, entrepreneurship, and building financial businesses with the next generation of business leaders.
Recognition and Professional Involvement
In 2013, Len received the M&A Advisor’s Lifetime Achievement and Leadership Award and was inducted into the M&A Advisor Hall of Fame, recognizing his contributions to the financial services and middle-market investment industry.
Throughout his career, Len has remained active in organizations spanning business leadership, investing, entrepreneurship, education, and civic engagement.
His affiliations include membership on the Wharton Graduate Executive Board, reflecting his longstanding connection to the Wharton School and his continued engagement with the broader business and investment community.