William Chisholm

A group led by William Chisholm and backed by private equity fund Sixth Street has reached an agreement to buy the Boston Celtics, according to multiple people familiar with the agreement, in what will be the most expensive NBA team sale in history. The managing partner of Symphony Technology Group, Chisholm has agreed to buy the team in two stages, which was the stated goal of the Celtics’ current ownership, led by the Grousbeck family. The deal values the team at $6.1 billion in the first payment. Chisholm 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 STG, which is based in Menlo Park, Calif. STG’s portfolio includes more than 50 active and closed investments, with about $10 billion of assets under management, as of March 2023. Prior to starting STG, Chisholm co-founded The Valent Group, and he also worked at Bain & Company and PaineWebber.