William Chisholm Leads Bid for Boston Celtics in Historic $6.1 Billion Deal

In a landmark moment for professional sports, William Chisholm, a Massachusetts-born private equity titan and lifelong Boston Celtics fan, has spearheaded a consortium to acquire the storied NBA franchise for an unprecedented $6.1 billion. Announced on March 20, 2025, this deal not only shatters records as the most expensive sale of an NBA team but also stands as the most significant transaction for any North American sports franchise, eclipsing the $6.05 billion sale of the NFL’s Washington Commanders in 2023. For Celtics fans, the NBA, and the broader sports ecosystem, this acquisition marks the dawn of a transformative era for one of basketball’s most iconic teams.
The Man Behind the Bid
William Chisholm is a name well-known in finance and technology, though his leap into sports ownership has thrust him into a new spotlight. As the co-founder, managing partner, and chief investment officer of Symphony Technology Group (STG), William Chisholm has spent decades building a powerhouse private equity firm based in California.
Founded in 2002, STG manages roughly $10 billion in assets and oversees a portfolio that includes over 50 active and closed investments, primarily in the tech sector. Before launching STG, Chisholm co-founded The Valent Group, a boutique consultancy, and held roles at Bain & Company and PaineWebber, sharpening his skills in strategy, finance, and investment.
A graduate of Dartmouth College with an MBA from the Wharton School at the University of Pennsylvania, William Chisholm’s credentials are impeccable. Yet, it’s his personal story that resonates most in this deal.
Raised in Georgetown, Massachusetts, William Chisholm grew up immersed in Celtic culture, cheering for legends like Larry Bird and dreaming of the team’s green-and-white glory days. That childhood fandom has now culminated in a historic opportunity to own the team he’s loved his entire life, blending business savvy with a deeply personal passion.

The Record-Breaking Deal
The $6.1 billion purchase, backed by substantial financing from private equity giant Sixth Street (which contributed over $1 billion), is a complex transaction structured in two phases. This structure aligns with the estate planning objectives of the Grousbeck family, who have owned the Celtics since 2002 when they acquired the team for a modest $360 million—a figure that pales in comparison to today’s valuation.
The initial payment values the Celtics at $6.1 billion, with a blended valuation expected to reach approximately $6.6 billion upon completion of the second stage in 2028. Wyc Grousbeck, the current governor, will remain in his role through the 2027–28 season, providing a transitional bridge as the William Chisholm group takes the reins.
The consortium includes prominent figures like Rob Hale, an existing Celtics investor, and Bruce A. Beal Jr., president of Related Companies, reflecting the collaborative heft behind this bid. The $6.1 billion price tag obliterates the previous NBA record of $4 billion, set by Mat Ishbia’s purchase of the Phoenix Suns, and underscores the explosive growth in sports franchise valuations.
Multiple suitors vied for the Celtics, including Phillies owner Stan Middleman, the Friedkin Group (owners of the Houston Rockets), and current Celtics minority owner Steve Pagliuca. Yet, William Chisholm’s group emerged victorious, a testament to their financial firepower and strategic vision.
Why the Celtics Are Worth It
The Boston Celtics are not just a basketball team—they’re a cultural institution with a legacy unmatched in the NBA. Tied with the Los Angeles Lakers for the most championships in league history at 18, the Celtics added their latest banner in June 2024, defeating the Dallas Mavericks in a thrilling Finals series.
This recent triumph, paired with a rabid fanbase and a storied past featuring icons like Bill Russell, John Havlicek, and Paul Pierce, has propelled the team’s value skyward. Sportico recently pegged the Celtics’ worth at $5.66 billion, but William Chisholm Group sees an even greater upside, justifying their record-setting investment.
Despite not owning TD Garden (where they play as tenants) and holding only a minority stake in their local media partner, the Celtics’ on-court success and brand equity have made them a crown jewel of the NBA. The team’s combination of historical prestige and current competitiveness—led by stars like Jayson Tatum and Jaylen Brown—creates a potent mix that few franchises can rival. This deal sets a new benchmark for sports franchise sales, with ripple effects likely to influence valuations across the NBA, NFL, MLB, and beyond.

The Financial and Competitive Landscape
William Chisholm inherits a Celtics team at the peak of its powers but facing significant financial challenges. Boston’s current roster, while championship-caliber, is among the league’s most expensive. The team’s payroll for the 2024-25 season has already triggered a $50 million luxury tax penalty, a number projected to balloon further without roster adjustments.
Key players like Tatum, Brown, and Derrick White are locked into lucrative long-term contracts, ensuring continuity but also straining the salary cap. For William Chisholm, balancing this financial burden with the pursuit of additional titles will be a delicate dance.
The NBA’s evolving economic landscape adds another layer of complexity. With a new media rights deal on the horizon and potential salary cap increases, the Celtics’ revenue potential could grow, offsetting some of these costs. However, William Chisholm’s private equity background suggests a data-driven approach to ownership, one that may prioritize profitability alongside championships—a shift that could test the patience of a fanbase accustomed to winning.
A Transition with Stability
Wyc Grousbeck’s decision to stay on as governor until 2028 offers a buffer for Chisholm and his team to acclimate to NBA ownership. Grousbeck, who led the Celtics to two championships during his tenure (2008 and 2024), has earned the trust of players, coaches, and fans alike.
His continued presence ensures that the organization’s culture—built on discipline, teamwork, and a relentless pursuit of excellence—remains intact during the ownership transition. Players like Tatum have voiced optimism about the sale, emphasizing their desire for stability as they chase more hardware.
For William Chisholm, this period will be a chance to learn the intricacies of running an NBA franchise, from navigating league politics to managing fan expectations. His experience at STG, where he’s overseen complex investments and turnarounds, should serve him well, though the emotional stakes of sports ownership differ vastly from the tech world.

A New Chapter for Celtics Nation
The $6.1 billion sale of the Boston Celtics is more than a financial milestone—it’s a symbolic passing of the torch. For William Chisholm, it’s the realization of a lifelong dream—a chance to leave his mark on a franchise that shaped his identity as a Massachusetts kid. For Celtics fans, it’s a moment of anticipation and uncertainty: Will this new ownership group uphold the team’s championship tradition, or will financial pragmatism take precedence?
As the deal moves toward its final stages, the basketball world watches with bated breath. The Celtics, fresh off a title and armed with a generational roster, are poised for continued success. William Chisholm’s leadership, backed by a consortium of heavy hitters, signals a bold vision for the future—one that could cement Boston’s place atop the NBA for years to come. At $6.1 billion, the price reflects the Celtics’ towering value, both as a competitive force and a cultural touchstone. For William Chisholm and the Celtic Nation, the journey is just beginning, and the stakes have never been higher.