Inside the Billion-Dollar Boston Celtics Sale: What the Chisholm Group’s Takeover Means for the Future of the Franchise

In March, Chisholm’s group reached a deal to buy the Celtics in two stages, which was the stated goal of ownership, led by the Grousbeck family. The deal valued the team at .1 billion in the first payment, marking the most expensive control sale in sports team history at the time—Mat Ishbia’s billion Phoenix Suns buy in 2022 was the prior record. It has since been surpassed by Mark Walter’s billion purchase of the Los Angeles Lakers.

The NBA Board of Governors unanimously approved the sale of the Boston Celtics to a group led by William Chisholm, the league announced Wednesday. The deal is expected to close by the end of the week.
The investment group also includes Rob Hale, who was a previous Celtics investor and is raising his stake in the deal, as well as Bruce A. Beal Jr., president of Related Companies.

Aditya Mittal will be the second-largest stakeholder in the Celtics and likely replace Grousbeck as alternate governor after the 2027-28 season. Mittal is the son of Lakshmi Mittal, who serves as executive chairman of billion-in-revenue ArcelorMittal, the world’s second-largest steel and mining company after China’s state-owned Baowu. Lakshmi started Mittal Steel in the late 1980s and merged the company with France’s Arcelor in 2006. He is worth billion, according to Bloomberg.

The Grousbecks bought the team in 2002 for 0 million. Last July, they announced the franchise was for sale, less than two weeks after winning an NBA-record 18th championship. The stated reason was estate planning.

The 2024-25 Celtics season had a jarring finish as All-NBA star Jayson Tatum tore his Achilles tendon during the Eastern Conference semifinals against the New York Knicks, and Boston lost the series. A long recovery is ahead, and the club has since traded a pair of key players in the 2024 title run, Kristaps Porzingis and Jrue Holiday, which will save Boston an estimated 0 million in luxury tax penalties next season, according to ESPN’s Bobby Marks.

Private equity giant Sixth Street was part of Chisholm’s initial group when the agreement was reached. The firm, which also owns a stake in the San Antonio Spurs, will be the third largest shareholder, just behind Mittal. The NBA’s private equity rules cap the stake that a single firm can own at 20% of the team.

Goldman Sachs was the financial advisor for the Chisholm group. BDT & MSD and JPMorgan Chase co-led the sale process for the Celtics. Jordan Park served as an advisor the Grousbecks.

Chisholm, who will be the lead investor, was born and raised in Massachusetts and attended Dartmouth College, as did two of his children. He is the co-founder, managing partner and chief investment officer of private equity firm STG Partners, which is based in Menlo Park, Calif. STG’s portfolio includes more than 50 active and closed investments, with about billion of assets under management, as of March.

Chisholm will replace Wyc Grousbeck as governor in a switch from Grousbeck’s orginal plan to stay in place in the role through the 2027-28 season.

On Tuesday, Sportico broke the news that a group led by Tom Dundon reached a deal to buy the Portland Trail Blazers at a .25 billion valuation. Assuming that deal and the Lakers’ one are approved, it would mark the 14th NBA control sale since 2013.

The NBA just flipped the script on one of its iconic franchises — the Boston Celtics have officially changed hands. William Chisholm now leads the new ownership group, a move the NBA Board of Governors greenlit unanimously this Wednesday. This transaction, poised to finalize by week’s end, marks a pivotal shift as Chisholm steps up to replace Wyc Grousbeck sooner than expected, shaking up plans once set to extend through the 2027-28 season. Valued initially at a staggering .1 billion, this deal not only set a record but also underscores the escalating value of NBA control stakes in today’s sports landscape — right on the heels of recent heavyweight sales involving the Lakers and Trail Blazers. With Chisholm’s deep Massachusetts roots and sharp private equity acumen steering the helm, plus heavyweight investors like Aditya Mittal and Sixth Street rounding out the leadership, the Celtics’ future under new stewardship is something every basketball aficionado will want to watch closely. Curious for more on this groundbreaking sale and the players behind it? LEARN MORE.