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The Watermill Group
The Watermill Group was founded in 1974 as a family office for the Karol family, with Steven Karol joining the firm in 1980 and later becoming its...
The Watermill Group
The Watermill Group was founded in 1974 as a family office for the Karol family, with Steven Karol joining the firm in 1980 and later becoming its Managing Partner. The firm operates out of Lexington, Massachusetts, with a team of approximately 30 professionals spanning investment, operations, and advisory functions. Its wealth originates from private family sources, though the exact origin is not publicly detailed by the firm. The firm pursues control-oriented private equity investments in North American middle-market companies, typically investing $20 million to $100 million per deal. Target sectors include industrial technology, healthcare services, business services, and consumer products. The Watermill Group structures transactions as long-term hold investments, often retaining portfolio companies for over a decade. Notable investments include the acquisition of Ametek's specialty metals business and the growth of portfolio company The Foxboro Company (per public record). The firm also manages a real estate portfolio through Watermill Properties, focusing on commercial and industrial properties in the Northeast. The Watermill Group has maintained a steady team structure with Steven Karol and his son Erik S. Karol as Managing Partners. The firm operates with a permanent capital base, allowing it to avoid the pressure of traditional fund raise cycles. In May 2026, the firm was active in evaluating new platform investments in the industrial technology sector (per industry sources). Adjacent activities include a philanthropic foundation, the Karol Family Foundation, which supports education and community development. A structural differentiator for The Watermill Group is its permanent capital model — it does not raise time-bound private equity funds, instead investing family capital alongside select co-investors on a deal-by-deal basis. This structure allows the firm to hold assets through economic cycles without forced exits, and to engage in operational turnarounds that may require multi-year time horizons. The firm also offers advisory services to family offices and closely-held businesses through a separate consulting arm, distinguishing it from pure investment firms.
General information
Firm type
Multi Family Office
Year founded
1974
AUM
Undisclosed
Location
Region
North America
Country
United States
City
Lexington
Corporate office
Lexington, MA, United States
Principals
Steven Karol
Managing Partner
Erik S. Karol
Managing Partner
Sector focus
Frequently asked questions
Who runs investment decisions at The Watermill Group?
Steven Karol, Managing Partner, has led the firm since 1980. His son Erik S. Karol also serves as Managing Partner, with both sharing responsibility for deal sourcing, underwriting, and portfolio oversight.
How does The Watermill Group source proprietary deal flow?
The firm relies on an in-house team for direct sourcing, supplemented by relationships with middle-market intermediaries, investment banks, and an extensive network built over decades. The Watermill Group often targets businesses where it can apply operational improvements as a differentiating factor.
Is The Watermill Group structured as a single family office or does it operate more like a private equity firm?
It is a multi-family office that operates with the strategies of a private equity firm, but using permanent capital from the Karol family and select co-investors. It does not raise traditional closed-end funds, allowing for longer hold periods.
What investment stages does The Watermill Group typically target?
The firm focuses on control acquisitions of lower-middle-market companies, typically with enterprise values between $50 million and $200 million. It invests across both growth and turnaround scenarios, preferring businesses where operational changes can drive value.
Does The Watermill Group maintain philanthropic structures?
Yes, the Karol Family Foundation is the firm's philanthropic vehicle, supporting education, community development, and other causes in Massachusetts and beyond. It is managed separately from the investment operations (per public record).
What sectors does The Watermill Group avoid?
The firm typically avoids early-stage or venture capital investments, as well as assets requiring significant regulatory licensing in financial services. Its focus remains on industrials, healthcare services, and business services where operational expertise can be applied.
How does The Watermill Group relate to other Karol family entities?
The Watermill Group is the primary family office for the Karol family, directly managing their investment portfolio and operating companies. It also provides advisory services to other families and closely-held businesses through a separate consulting practice, but does not commingle capital with outside LPs.
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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