The Largest Family Offices in the US

A single-family office runs one family's wealth as a private investment firm; the largest American offices operate at the scale of major institutions. Walton Enterprises, the Bentonville hub for Walmart's founding family, leads at an estimated $225 billion, built around the family's large Walmart stake and diversified through public equities and satellite vehicles such as Builders Vision; the family's combined net worth exceeds $280 billion, per Bloomberg. Cascade Investment ranks second at an estimated $115 billion; that figure covers Bill Gates's personal assets only, because the Gates Foundation Trust the office also manages is a separate pool and is not counted here. Bezos Expeditions, at roughly $105 billion on an office basis, is the most active dealmaker of the group, spanning venture bets across AI and biotech, aerospace through Blue Origin, and the Washington Post. Nearly every number on this page is a third-party estimate; no office here publishes audited AUM.

Cascade shows what the biggest offices actually do with the money. Under Michael Larson, chief investment officer since 1994, Bill Gates's office diversified Microsoft wealth into long-horizon positions: roughly 270,000 acres of farmland, majority ownership of Four Seasons, large public stakes in Berkshire Hathaway and Waste Management, and about $42 billion of securities visible in the Gates Foundation Trust's SEC 13F filings, a separate pool Cascade's team also runs. DFO Management, Michael Dell's office, shows the limits of measuring any of this: published estimates run from about $50 billion to $110 billion, a spread wider than most entire family offices, because DFO discloses nothing and outsiders triangulate from stakes and deals. The two even overlap — Cascade controls Four Seasons the company, while DFO's real estate arm owns Four Seasons hotels. That opacity, more than any ordering dispute, is the defining feature of the category.

The United States dominates the category outright. The country hosts about 7,160 family offices, the most of any jurisdiction, with Singapore a distant second at roughly 2,720, per PwC's Global Family Office Deals Study. Of the 50 largest family offices worldwide, which together manage an estimated $2.4 trillion, 24 are American, and North America's 28 entries account for roughly $1.55 trillion of the total. Half of the offices that disclose manage at least $2.5 billion, and North American offices post the highest average AUM of any region. The population keeps compounding: the global family-office count roughly tripled between 2019 and 2023, and Altss now tracks more than 9,000 family offices worldwide. Each entry below links to its Altss profile, covering leadership, filings, and recent activity.