Grant Thornton Advisors moves to acquire M&A consultancy Stax
ILLINOIS and MASSACHUSETTS, UNITED STATES — Grant Thornton Advisors LLC, the advisory arm of Grant Thornton US, has announced its intention to acquire Stax, a Boston-based mergers and acquisitions (M&A) consulting specialist.
The deal, expected to be completed later this year, aims to expand Grant Thornton’s commercial diligence and value creation offerings, particularly for private equity (PE) clients.
Established in 1994, Stax is renowned for its proficiency in commercial due diligence, value creation, and exit planning. The firm’s 300 employees, spread across the United States, the United Kingdom, and Sri Lanka, serve a diverse base ranging from large-cap to mid-market private equity firms, alternative asset managers, and investment banks.
Grant Thornton Advisors already claims over 600 PE relationships, including ties with 60% of the world’s top 10 global PE firms by equity.
“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.
Grant Thornton’s accelerated growth backed by private equity
This acquisition marks the latest milestone in Grant Thornton’s period of accelerated expansion following the 2024 majority investment by New Mountain Capital, a prominent New York-based PE firm.
In 2025 alone, Grant Thornton has integrated member firms from Ireland, the United Arab Emirates, Luxembourg, the Cayman Islands, the Netherlands, Switzerland/Liechtenstein, and the Channel Islands, advancing its international reach.
Notably, just a month prior, Grant Thornton US acquired Auxis, a Fort Lauderdale-based business process outsourcing (BPO) provider employing 1,400 professionals—primarily in Latin America—a move that further sharpened Grant Thornton’s outsourcing delivery capabilities.
Grant Thornton, operating under an alternative practice structure that separates audit and advisory arms, now employs approximately 13,000 across the Americas and EMEA.
Jayson Traxler, CEO of Stax, highlighted, “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.”
Merger to serve majority of leading private equity firms
Both Grant Thornton US and Stax are established leaders in the consulting and outsourcing sectors. Grant Thornton has aggressively expanded its workforce and BPO operations in the Americas, while Stax’s due diligence and value-focused services have earned it a high-profile clientele.
The merger will allow the combined entity to serve nearly 70% of U.S.-based firms listed in the Private Equity International 300, further consolidating its position in private equity transaction support and outsourcing service delivery.
Financial advisors on the transaction included Clearsight Advisors and Harris Williams for Grant Thornton, and William Blair and Stout for Stax.
Grant Thornton provides professional services in the United States through two entities: Grant Thornton LLP, a licensed, certified public accounting (CPA) firm that provides audit and assurance services; and Grant Thornton Advisors LLC, which is not a licensed CPA firm and exclusively provides non-attest offerings, such as tax and advisory services.
Grant Thornton recently ranked #34 in the OA500 2025, an objective index of the world’s top 500 outsourcing companies.
