A family office now turns up in transaction documents in a role once reserved for banks and buyout funds. The merger file of Warner Bros. Discovery records a personal and trust guarantee covering $45.72bn of the merger consideration. It takes up a single line. That line commits more capital than most private equity firms manage in total, and I can measure it against the only published census of the sector that carries a method.
The guarantee sits in the WBD quarterly filing for the period ended 30 June 2026. The Form 10-Q says that "Larry J. Ellison and an affiliated trust entered into a guarantee in favor of WBD to, among other things, jointly and severally guarantee certain payments by PSKY under the PSKY Merger Agreement, including $45.72 billion of the aggregate Merger Consideration, and assist WBD with the consummation of the PSKY Merger." The deal is the Paramount Skydance acquisition.
I keep rereading the last clause. The guarantor undertakes not only to pay but to assist with completion. That is a commitment of influence rather than of capital. Investment funds rarely sign language like that.
For a seller, a guarantee is the document that answers whether private capital can perform. I would read the guaranteed amount against the total consideration, not against the guarantor's reputation.
The merger consideration is $31.00 per share. The WBD Form 10-Q cover data, pulled through SEC XBRL, gives 2,510,703,314 shares outstanding on 23 July 2026. Multiply the two and aggregate equity consideration comes to $77.83bn. The guarantee covers 58.7% of that.
That total is my number, not a disclosed one. No party has published the aggregate merger consideration. My calculation assumes every outstanding share receives $31.00, which overstates the total wherever the stated exceptions apply, so the true coverage is probably a little higher than 58.7%, though I cannot say by how much.
The sector figures come from Deloitte Private's 2024 family office study. It counts 8,030 single family offices worldwide. Surveyed offices report "average assets under management (AUM) of US$2.0 billion", and the study states that "family offices' total estimated AUM currently stands at US$3.1 trillion", while total family wealth behind them rose from $3.3trn in 2019 to $5.5trn, "reflecting a 67% increase within five years".
The population is growing as well. Deloitte reports growth "from 6,130 in 2019, a near third (31%) increase" to today's 8,030. It projects a further rise "by a third (33%) to 10,720 family offices by 2030". I find the direction more telling than the level. Private capital has been consolidating into fewer, larger single-family vehicles. Those vehicles face materially lighter disclosure obligations than registered funds.
For sellers the consequences are practical. Such a counterparty can commit faster than a fund bound by an investment committee and a fixed fund life. It may also be missing from the usual databases altogether, which leaves covenant and guarantee analysis as the only reliable route to establishing who stands behind the money. The M&A deals base on this site records comparable buyer structures.
Divide $45.72bn by $3.1trn and you get 1.47%. One individual and one trust have guaranteed a sum equal to about one part in sixty-eight of every dollar managed by every single family office in the study.
Against the average office it looks stranger still. The guarantee is 22.9 times the $2.0bn average. Spread across all 8,030 offices, it would come to $5.69m each. Advisers should not treat it as representative of family office capacity.
I also ran it against the future. Deloitte projects $5.4trn of sector assets by 2030, and on that figure the guarantee falls to 0.85%. Even on the forward number it stays a material fraction of a sector measured in trillions.
The 58.7%, the 1.47%, the 22.9 times and the $5.69m are M&A House calculations. The denominators are Deloitte estimates rather than a registry count, because single family offices are not required to report assets. I have no better census to check them against.
Belén Villalonga and Raphael Amit published "How do family ownership, control and management affect firm value?" in the Journal of Financial Economics in 2006, volume 80, issue 2, pages 385 to 417. The Crossref record is verified, and the working paper abstract sits under DOI 10.2139/ssrn.556032.
The method used "proxy data on all Fortune 500 firms during 1994-2000". It pulled apart ownership, control and management, which are usually bundled together. That separation produced the central result. The authors find that "family ownership creates value only when the founder serves as the CEO of the family firm or as its Chairman with a hired CEO".
The negative findings in the paper are sharper. "Control mechanisms including dual share classes, pyramids, and voting agreements reduce the founder's premium. When descendants serve as CEOs, firm value is destroyed." The authors also conclude that the conflict between family and non-family shareholders in descendant-led firms costs more than the ordinary owner-manager conflict elsewhere.
What I take from it is about generation and structure, not wealth. Family capital is not a single asset class with a single governance profile, and diligence that stops at the size of the balance sheet has skipped the variable the research identifies. Whether the founder or a descendant controls the vehicle is a question with a factual answer.
Scale is not the same as prudence, and the counter-example comes from the same structure. Archegos was also a family office. The SEC charged its owner in April 2022 with "orchestrating a fraudulent scheme that resulted in billions of dollars in losses" and called the firm a "$36 billion house of cards".
The SEC described a firm "increasing in value from approximately $1.5 billion with $10 billion in exposure in March 2020 to a value of more than $36 billion with $160 billion in exposure at its peak in March 2021". On my arithmetic from those figures, exposure to value stood at 6.7 times in March 2020. A year later it was 4.4 times.
The ratios move in the opposite direction to intuition. Reported gearing fell while absolute exposure grew sixteenfold. Any screen watching the ratio alone would have logged an improvement. For banks and counterparties, the regulator's own numbers show a gearing ratio improving while exposure compounds.
FINMA closed its proceedings in July 2023. It found that "Credit Suisse had seriously and systematically violated financial market law in the context of its business relationship with the Archegos family office". It noted that "Credit Suisse suffered the biggest loss of over USD 5 billion".
Lighter disclosure cuts both ways for founders raising from private capital. It is why the venture capital and private equity comparisons matter, alongside the definition of a family office itself. The Ellison guarantee and the Archegos book both came from the same kind of vehicle, and I still cannot tell, from the public filings alone, which of the two is closer to the norm for the 8,030 offices Deloitte counted.