Chicago-based IPA 100 firm Grant Thornton (FY24 net revenue of $2.4 billion) announced it will acquire Boston-based Stax, a leading strategy consulting firm specializing in commercial due diligence, value creation and exit-planning services for private equity (PE) firms, as well as their portfolio companies and advisers. 

Stax is a 30 year old firm that has grown rapidly in recent years, while maintaining high client-retention rates and lengthy stakeholder relationships. It serves many of the leading players in large-cap and middle-market PE, alternative investments and investment banking. 

Grant Thornton is backed by an investor group led by New Mountain Capital, a growth-oriented investment firm with approximately $55 billion in assets under management.

“With this bold move, we’re taking our platform to new heights — combining Stax’s top-tier talent with our own industry-leading professionals, while broadening our offerings and further elevating our tech capabilities,” said Jim Peko, CEO of Grant Thornton Advisors. “Stax has a decades-long legacy delivering transformative value to clients — similar to our own 100-year history. Together, we will generate bold results for a PE client base stretching from the Americas across Europe to the Middle East.” 

“PE firms today don’t just want an adviser; they want a partner with agility, intelligence and scale,” said Tom Puthiyamadam, MP for Advisory Services at Grant Thornton Advisors. “By adding Stax, we’re combining trust with data-driven precision to unlock strategic value at every stage of the investment lifecycle. This is more than an expansion — it’s a leap forward in delivering outcomes for PE and corporate clients.” 

According to Jayson Traxler, CEO of Stax: “We are proud to have built a 30-year reputation for excellent client service, unique tech-enabled solutions and impressive growth. As part of Grant Thornton Advisors, those characteristics will endure — but with far greater scale, speed and amplification of our impact. We will be empowered to build on our unique strengths and insights, for the benefit of the leading PE firms, portfolio companies and investment banks.” 

Stax’s approximately 300 team members will join Grant Thornton Advisors when the transaction closes, which is expected to take place in 2025, subject to standard closing conditions.