A Boston-area native and Ivy League soccer player who grew up a Celtics fan, William Chisholm has spent more than two decades working out of the limelight, buying and selling software firms—and making a killing.
William “Bill” Chisholm just clinched the biggest pro-sports deal in history, leading a group of investors with an agreement to buy the NBA’s Boston Celtics for $6.1 billion. Chisholm and his co-investors are buying the defending NBA champions from Boston’s Grousbeck family, who led the purchase of the Celtics for $360 million in 2002 and have overseen the team as its value has soared. Forbes valued the Celtics at $6 billion in October, making Irving Grousbeck and family billionaires, worth $2.2 billion.
How did this little-known private equity executive pull it off? Mainly through decades of under-the-radar dealmaking—buying, improving and selling enterprise software companies for sometimes outsized profits.
Bill Chisholm has won the respect of many in the process of clinching the bid to buy the Celtics.
Courtesy Bill Chisholm
The Dartmouth and Wharton grad had been running a small venture capital firm when, in 2002, Silicon Valley billionaire Romesh Wadhwani brought him on as his senior investment partner at a new software-focused private equity firm, Symphony Technology Group, that was initially funded with Wadhwani’s money—earned by the sale in 2000 of a software firm he founded, Aspect Development, to i2 Technologies for $9.3 billion in stock. Over the next 15 years, Wadhwani tells Forbes, Symphony invested $1.6 billion of capital and returned $10 billion to investors. The firm bought middle-market software companies, improved their operations while shunning the use of excessive debt, and sold them for many multiples of what they paid. Symphony started four companies and purchased 21 others. A signature deal: It picked up market research firm Information Resources—later renamed iRi and now called Circana—for less than $120 million in 2003 and sold most of it at a $1 billion valuation in 2011.
“We focused on value creation through operational improvement rather than through using debt,” says Wadhwani. “I didn’t want to use financial engineering.”
In 2017, Wadhwani wanted to switch his focus, so he retired as CEO of Symphony Technology Group to launch an AI investing firm. Chisholm took the top job, and rebranded Symphony as STG Partners. It now has $11.7 billion in assets under management. Chisholm, 56, is the principal owner of the firm, with more than 50%, according to securities filings. Petershill Partners, a subsidiary of Goldman Sachs that buys pieces of other private equity firms, invested $60 million into the business in 2021 for a minority stake.
Forbes calculates that Chisholm is worth north of $3 billion—up from an earlier estimate of at least $1 billion. The upward revision is based on additional information that led to a higher estimated value of STG Partners, of which Chisholm owns an estimated 60% stake. He owns at least four homes and apartments in California and New York City that are worth an estimated $30 million, plus a home on Nantucket, according to the Boston Globe. A spokesperson for Chisholm declined to comment on his fortune.
The NBA requires that the principal owner of a team own at least 15% of it, so Chisholm will likely be putting down at least $915 million for his stake. But he may not have to put that entire amount in right away since the purchase is a two-stage process. Irving Grousbeck’s son Wyc Grousbeck is staying on as CEO and governor of the Celtics through the 2027-2028 season, when the second part of the Celtics sale will close.
Bill’s “love for the team and the city of Boston, along with his chemistry with the rest of the Celtics leadership, make him a natural choice to be the next governor and controlling owner of the team,” Grousbeck said in a statement announcing the deal. “I know he appreciates the importance of the Celtics and burns with a passion to win on the court while being totally committed to the community.”
Bruce Beal Jr., president of New York real estate firm Related Companies, joined as one of the new investors in the Celtics.
Bryan Bedder/Stringer/Getty Images
Other investors in the group include private equity firm Sixth Street Partners; Bruce Beal Jr., the president of New York-based real estate developer Related Companies; and current Celtics minority shareholder Rob Hale, a Boston-based telecom billionaire. Beal, who first joined real estate mogul Stephen Ross’ Related Companies in 1995, is also a minority owner of the NFL’s Miami Dolphins and held on to his stake after Ross sold 13% of the team (plus Hard Rock Stadium and Formula 1’s Miami Grand Prix) at a combined $8.1 billion valuation in December.
Hale says he’s increasing his stake in the Celtics but wouldn’t say what his stake will be. “It’s bigger than a bread box,” he jokes. Hale says he had never heard of Chisholm until he was introduced to him through bankers who did an “extensive search” for potential buyers. Asked why he would team up with a guy he hadn’t known, Hale says: “I met with Bill dozens of times. I had a very high-level confidence in Bill and immediately hit it off with him. As soon as you meet him, he comes across as a really nice guy, accomplished, modest. He immediately came across as an ethical, compassionate, focused leader.”
Chisholm may still be looking for more investors. He offered one billionaire the opportunity to buy a stake in the team Thursday, according to the billionaire.
This buyer likely won’t have too tough a time winning folks over. Chisholm, says Wadhwani, “had very good business instincts, was incredibly thorough in terms of doing due diligence, and was very charming in dealing with the sellers,” meaning software firms. Landing the firms you want to buy is crucial for success, explains Wadhwani. “You have to convince the seller to go with STG rather than KKR or Vista or Thoma Bravo.”
A Georgetown, Massachusetts native, Chisholm attended his first Celtics game on his seventh birthday, he told ESPN’s Shams Charania, adding: “I’ve been a rabid fan ever since. I bleed green. I love the Celtics.”
He bled green at Dartmouth, too, where he was a member of the men’s varsity soccer team that won Ivy League titles in 1988 and 1990. Says Ross Mandell, a friend and former teammate of Chisholm’s who works at IMG, “Bill helped me push through that tough freshman year and was a role model to many teammates as he went from no playing time freshman year to being an integral part of a two-time Ivy League championship team.”
“I expect that (Bill) will continue in the same collaborative fashion as Wyc did, which makes it more fun to be part of the team,” says Rob Hale, a Boston-based telecom billionaire and minority owner of the Celtics who is a part of Chisholm’s investor group.
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Also classmates and teammates of Chisholm’s at Dartmouth: Gregg Lemkau, the co-CEO of BDT & MSD Partners, the merchant bank that was one of the financial advisors on the Celtics sale (Lemkau was a goalie), and Richie Graham, founder of investment firm Striker Partners and an investor in Major League Soccer’s Philadelphia Union. CNN anchor Jake Tapper was Chisholm’s fraternity brother at Alpha Chi Alpha.
Chisholm met his now-wife, Kimberly Ford, at Dartmouth. She has a Ph.D. from the University of California, Berkeley in Spanish and French literature and in 2008 wrote a well-reviewed book called Hump: True Tales Of Sex After Kids, dedicated to Bill. The couple have three children, the oldest of whom, Will, was diagnosed with Type 1 Diabetes and went on to play soccer at Dartmouth. Soon after his diagnosis, Kimberly Chisholm joined Breakthrough T1D Bay Area’s executive board as vice president of research and major gifts from 2010 to 2013 and wrote a weekly blog for them.
A move back to the Boston area seems almost guaranteed. “I understand how important the Celtics are to the city of Boston—the role the team plays in the community is different than any other city in the country,” Chisholm said in a statement. “I also understand that there is a responsibility as a leader of the organization to the people of Boston, and I am up for this challenge.”
Chisholm’s former soccer teammate Mandell concurs: “Many times, professional sports franchise owners are not approachable or buy the team for the wrong reasons. Bill is the most likable guy, is a self-made person who earned his stripes and will be a tremendous enhancement to the Celtics culture moving forward.”
He won over Grousbeck and Hale, who adds: “Nice guys can win. I’ve gotten a lot of notes about that in the past few days.”
With reporting by Matt Durot, Luisa Kroll, Giacomo Tognini, Hank Tucker, Justin Birnbaum and Brett Knight.
Editor’s note, March 24, 2025: This article has been updated with a higher net worth estimate for Bill Chisholm based on additional reporting.
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