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UBMB
UBMB operates as the private investment company of Christopher S.
UBMB
UBMB operates as the private investment company of Christopher S. Gaffney, co-founder and Managing Partner of Great Hill Partners, the Boston-based growth-equity firm with over $12 billion in aggregate commitments raised. The firm's ownership is structured within the Gaffney family, with the CS Gaffney and KA Kames 2017 Irrevocable Trust holding 98 percent for the benefit of the Gaffney children, and KA Kames retaining a 1 percent stake. The firm's investment strategy centers on early-stage venture, targeting seed-stage technology companies. UBMB deploys capital through direct investments and co-investments alongside specialized venture managers. Glasswing Ventures, a Boston-based firm investing in early-stage AI and frontier technology startups, has been a frequent co-investor. The strategy draws on Gaffney's broader network within private equity and growth investing, creating a bridge between institutional buyout discipline and early-stage technology exposure. The firm's footprint extends beyond its Boston headquarters, with family-held assets including a residential property in Tulsa, Oklahoma and a community transport van. Known philanthropic commitments include support for the Special Olympics of Massachusetts, reflecting a local, family-oriented operational style. No dedicated investment professionals beyond Gaffney are documented in the firm's structure. UBMB's architecture is defined by its hybrid posture: a single-family investment office that shares leadership with a major institutional growth-equity firm. This overlap places Gaffney at both ends of the capital deployment spectrum, from minority seed checks to control-stake investments in scaled companies, potentially offering a sourcing advantage that few individual investment vehicles possess.
General information
Firm type
Generalist
Year founded
—
AUM
Undisclosed
Location
Region
North America
Country
United States
City
Boston
Corporate office
Boston, MA, United States
Principals
Christopher S. Gaffney
Sole Manager
Frequently asked questions
Who runs investment decisions at UBMB?
Christopher S. Gaffney serves as the sole manager of UBMB, LLC. He co-founded Great Hill Partners in 1998 and remains a Managing Partner there, leading investments in growth-stage companies across software, fintech, and digital commerce. Investment decisions at UBMB flow through Gaffney directly, without a separate investment committee or dedicated staff.
How is UBMB related to Great Hill Partners?
UBMB is the personal investment company of Christopher Gaffney, who is also co-founder and Managing Partner of Great Hill Partners. UBMB is not a fund or affiliate of Great Hill; it is owned by the Gaffney family trust and operates independently. The connection is the shared leadership — Gaffney runs both entities — which creates overlap in sourcing and networks but no formal co-investment arrangement between the two.
Does UBMB invest directly or only through funds?
UBMB invests directly in seed-stage technology startups, often alongside venture capital co-investors such as Glasswing Ventures. The firm does not publicly disclose whether it also commits capital to third-party venture funds, but its documented activity points to direct equity stakes in early-stage companies rather than acting as a fund-of-funds.
How is ownership of UBMB structured?
The CS Gaffney and KA Kames 2017 Irrevocable Trust owns 98 percent of UBMB, LLC. KA Kames, Christopher Gaffney's spouse, owns the remaining 1 percent. This structure indicates the firm is designed as a long-term wealth vehicle for the Gaffney children, a common setup for single-family investment entities.
What is UBMB's known posture on co-investments alongside external GPs?
UBMB has a documented history of co-investing with Glasswing Ventures, a Boston-based firm focused on early-stage AI and frontier technology. This suggests a preference for partnering with specialist venture managers rather than leading rounds independently, though the firm has not published formal guidelines on minimums, stage limitations, or sector restrictions.
Profile maintained by Altss using OSINT (open-source intelligence), regulatory filings, licensed data partners, and verified direct submissions. Read the methodology. Last updated: . Continuous refresh with full update cycles at least every 30 days.
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