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An Investment Firm Focused on

Developing Companies

All About Grindstone Partners

Grindstone partners is a boutique, private equity investment firm that focuses on lower middle-market companies. The firm was founded in 2009, and we have over thirty years of experience working with companies in this marketplace. Our investment approach centers around a partnership with management, their capabilities, alignment, and desire to expand and professionalize the business.

We are active, hands-on investors and bring our capabilities and network to help management teams achieve their goals. We are different from other smaller private equity firms because of our collaborative approach to management, our economic alignment, fair goals, and our hard work with the team to ensure that we can deliver the expertise and value that the company needs.


Our founder, Michael Bluestein, brings over thirty years of financial experience working with lower middle market companies, and also has an extensive network of partners and resources to help management teams achieve their goals.  He is involved from beginning to end of an investment and does not expand his portfolio beyond his own capacity to serve his partners.  Grindstone Partners does not have a preset holding period for investments, nor is it subject to external fundraising milestones to exit its investments. 

Because each investment is considered stand alone, Grindstone can take a long term view and approach to each portfolio company.  Michael brings a realistic and practical approach to investing, based on business fundamentals, and alignment with the managers of the business.  Grindstone will often involve other experts or strategic capital sources in an investment if the firm and the management team believe it will be beneficial to the investment.

Alexandria Marsh -1

How It Began

Grindstone was founded during the financial crisis of 2008 to address a lack of value-add capital for small and medium sized companies. Middle market companies face challenges unique to founders, retooling for scale, executing on acquisitions, upgrading systems/processes/personnel, and accessing the right capital for the stage of their business.

It is critical for management to find the right investment partner who brings more than just capital to the table. Grindstone leverages its capabilities, experience and network to help management navigate and overcome its challenges. At Grindstone Partners, we succeed because our management teams succeed.


Sectors of experience include infrastructure services, building products, government services, niche manufacturing, outsourced business services and healthcare services. He has served on over two dozen company Boards and has advised many others. Prior to founding Grindstone Partners, Michael worked in the investment banking and private equity sectors for firms including Winston Partners, First Union and SunTrust.

Michael earned his BA from the University of Virginia and MBA in Strategic Management and Finance from the Wharton School at the University of Pennsylvania.  He has recently participated in non-degree classes in Data Science from the Darden School at the University of Virginia.


Building a plan to build an investment firm during a financial crisis is not for the faint of heart.  The market opportunity was crystallized and the plan was created in the summer of 2009, amid the splendor of the Thousand Island in upstate New York.  The firm was hatched in a family cabin on Grindstone Island on the St. Lawrence River.  The name embodies the solid granite foundation of our country, the simple laws of nature that planning and hard work always lead to better outcomes and the spectacular glory that can be achieved when you bring the right people and tools together working towards a common goal.

Michael Bluestein WEB