‘Never heard of the guy’

A finance guy named Bill Chisholm bought the famed Boston Celtics for $6.1 billion on Thursday — the most expensive sports franchise deal in US history.

 And yet, no one in the sports world or on Wall Street really knows who he is.

The mystery man is the co-founder of a private equity firm in Silicon Valley named Symphony Technology Group and based on his resume he has led deals to invest in mid-sized companies in the tech and software business.

“I’ve never heard of the guy,” said one top executive at a major sports franchise.

Which is why people are asking if Chisholm has the money necessary to make the deal work.

Symphony manages an estimated $10 billion in assets. By contrast the largest private equity firm, Blackstone Group, has  $1.1 trillion under management. Of course, he has other partners to finance the Celtics deal including Rob Hale, the billionaire president of Granite Telecommunications. Chisholm’s minority partner, the PE firm Sixth Street, is said to have thrown in $1 billion.

But these companies appear to be playing on a much bigger field than Chisholm and Symphony. Sixth Street has $100 billion in assets, and a significant footprint in the sports business.

The firm just bought a 10% stake in the San Francisco Giants to add to its roster of sports-related investments that include another NBA team, the San Antonio Spurs, and it might be best known here in New York for its majority stake in Legends Hospitality, co-founded by the New York Yankees and Dallas Cowboys.

Chisholm also has a low-key presence out in Silicon Valley, according to bankers who have worked with him. His resume includes co-founding something called the Valent Group, and years working at private equity powerhouse Bain Capital before founding Symphony in 2002.

“We bought a company from (Symphony), that’s how I know him. It still doesn’t add up. If he had billions, we’d know about him, or they would have a bigger fund at least,” one Silicon Valley PE executive told the Post.

Chisholm didn’t return a request for comment. In a statement released after the shocking sale, Chisholm said he’s a long-time Celtics fan who grew up in the Boston area and attended college in New England. “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. 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,” he chirped.

One thing is certain: Chisholm will likely need all the money he and his partners can drum up to keep the cast of defending NBA champs together – considering the hated Knicks rivals feature a roster projected to cost around $500 million for the 2025-26 season because of a luxury tax hit for blowing past the salary cap, as The Post previously reported.

Plus, he faces a headache about where his very expensive team plays. The Celtics don’t own their home arena TD Garden, a hospitality firm named Delaware North does.

There’s a lot of talk that he wants to build and own his own venue to generate the revenues needed to finance that expensive payroll, which means more billions.

To make it work the numbers work, sources say he can tap Wall Street sources.  Chisholm hired JPMorgan and its controversial but powerful wealth management chief Mary Erdoes (her unit allowed convicted pedophile Jeffery Epstein to do business with the bank long after he spent time in jail) to work on the deal, including putting the finishing touches on all the moving parts as news of the shocking sale became official, sources said.

And don’t forget, he managed to beat out several other bidders, including the team’s current minority owner Stephen Pagliuca and Stan Middleman, who owns a small stake in the Philadelphia Phillies, to convince the Celts majority owners, the Grousbeck family, to hand over the rights to the most storied franchise in the league.

The Grousbecks announced they were selling last summer just after winning their record 18th championship, citing “estate and family planning considerations.”

The Post previously reported that the father-son duo, Irving and Wyc, were at odds over how to manage the team’s massive payroll, the league’s largest.

The $6.1 billion deal, which is pending the NBA Board of Governors’ approval, would break the $6.05 billion record for a North American franchise that a group led by a much better-known Wall Street guy, Josh Harris, paid to scoop up the NFL’s Washington Commanders last year.

The Celtics deal would shatter the previous high in the NBA, set in 2023 when Mat Ishbia purchased the Phoenix Suns for $4 billion. Before that sale, the Milwaukee Bucks were sold for $3.5 billion, and last year Mark Cuban sold the majority of his Dallas Mavericks shares for $3.5 billion.

Additional reporting by Mark W. Sanchez