List of the 80 Largest Single Family Offices New York [2025]

List of 5 large New York Single Family Offices

With 123 billionaires and more than 800 individuals with wealth surpassing 100 million USD, New York is home to more billionaires than any other city in the world. This makes it one of the world’s leading hubs for family offices. The city’s appeal lies in its status as a global financial centre and its large population of billionaires and investment experts. This is supported by a strong legal infrastructure and access to top-tier financial services. Many of these high-net-worth individuals are looking for safe opportunities to expand their wealth further. They therefore often have their own family offices take care of this. Here, we present five of the largest single-family offices in New York, as featured in our list.

1. Mousse Partners

The Wertheimer family, led by brothers Gérard and Alain Wertheimer, owns and controls Chanel, one of the world’s most iconic luxury brands. Alain serves as chairman of Chanel, while Gérard, based in Switzerland, oversees the watch division. Their family office, Mousse Partners, operates with a high degree of discretion and is a core division of Mousse Investments Limited, founded in 1979. With offices in New York, Beijing, Hong Kong, and the Cayman Islands, Mousse Partners manages an estimated $90–100 billion in assets, a large portion of which is tied to Chanel. Beyond its ownership in Chanel, the firm invests across private equity, public markets, credit, and real estate. Notable investments include 66° North, Everplans, Storr, Evolved by Nature, and Thirty Madison. The office is led by Charles Heilbronn, the half-brother of Gérard and Alain, reflecting the family’s direct involvement in managing and growing its wealth.

2. DFO Management

The company serves as the private investment firm of Michael Dell and his family. Michael Dell, son of an orthodontist, started his studies in 1983 at the University of Texas to become a doctor. Instead of concentrating on his degree, however, he devoted himself to buying and selling IBM PCs, which led to dropping out of college just one year later. He then founded his company “Dell Technologies” with one of his fellow students at the age of 19 and started producing hardware.  MSD Capital was founded in 1998 and has its headquarters in New York, but also has established offices in Santa Monica and West Palm Beach. The investment focus lies on leveraged buyouts, growth capital, real estate, and private equity. One interesting exemplary investment of the recent past in terms of venture capital is “SparkCognition”, which they funded in a Series C funding session. SparkCognition is a global leader in cognitive computing analytics. A highly awarded company recognized for cutting-edge technology, SparkCognition develops AI-powered cyber-physical software for the safety, security, and reliability of IT, OT, and the IoT. The company’s technology is capable of harnessing real-time sensor data and learning from it continuously, allowing for more accurate risk mitigation and prevention policies to intervene and avert disasters. More recently, DFO Management backed 5C Investment Partners, a private credit firm launched by two former Goldman Sachs executives, providing both financial support and initial debt financing.

3. Willet Advisors

Willet Advisors, the family office of Michael Bloomberg, is based in New York City and mainly manages the billionaire’s philanthropic activities, including assets tied to his Giving Pledge commitment. Besides that, the office invests across a broad range of asset classes, including public markets, hedge funds, private equity, credit, real assets, and direct investments. So far, Willet Advisors has backed early-stage ventures such as TraceLink and Y Combinator, and holds a stake in Circle, the fintech company behind USDC, a U.S. dollar–backed stablecoin. More recently, the family office has turned its focus to healthcare, with investments in companies like Scorpion Therapeutics, Carmot Therapeutics, and Neurona Therapeutics.

4. Macanta Investments

Macanta Investments is the primary investment vehicle for Terence M. O’Toole and his family. Terence O’Toole is one of the founding members of the Principal Investment Area (“PIA”) at Goldman Sachs and became a partner in 1992. Since then, he has been a private investor, mainly in private companies. He retired from Goldman Sachs in 2004 and joined “Tinicum”, a 1 billion U.S. dollars private investment partnership, in 2005 as a managing member. He then founded Macanta Investments in 2016 to consolidate his family’s direct investing activity. The company strives for long-term investments in the private equity sector and makes both active control investments and also takes passive minority positions in businesses. Their focus is broadly diversified, ranging from software and the internet to industrial manufacturing. In 2017, Macanta Investments partnered with the Fremont Group, a California-based Single Family Office, which is listed among our Californian Single Family Offices List, and formed Fremont-Macanta LLC. Together, the two family offices seek to be long-term owners of high-quality businesses.

5. Ceniarth

Ceniarth is dedicated to the wealth of the Isenberg Family. Eugene “Gene” Isenberg, who passed away in 2014, was the chairman and CEO of Nabors Industries from 1987 to 2011. Nabors Industries is active in the field of oil exploration and oilfield services. Just after Gene joined the company, he immediately distinguished himself as one of America’s most gifted business strategists and dealmakers. Under his leadership, Nabors became a dominant player in gas and petroleum drilling markets in Alaska and the lower 48 U.S. states. The firm also excelled in Canada, Central and South America, the North Sea, the Middle East, Asia, Africa, and countries in the former Soviet Union. Gene also served as a director of the American Stock Exchange and the National Association of Securities Dealers. Ceniarth was founded by Eugene’s daughter, Diane Isenberg, in 2013 and is focused on funding market-based solutions that benefit underserved communities. Through their investing activity (mainly private equity and venture capital), they provide capital to accelerate the deployment of products and services that directly impact underserved communities. They aim to support enterprises in ways that lead to long-term commercial sustainability.

Available information in our New York single-family office list

• Company data (Company name, Legal form, Country of origin)
• Contact details (URL, address, e-mail, telephone number, executives)*
• Family information (Name, Estimated family assets in M€, Holding structure)*
• Area of activity
• Real Estate Focus (Yes/No) / Real Estate Focus Details / Example Real Estate Investments
• Venture Capital Focus (Yes/No) / Details on Venture Capital Focus / Examples of Venture Capital Investments
• Private Equity Focus (Yes/No) / Details on Private Equity Focus / Examples of Private Equity Investments
• Financial assets focus (Yes/No)
• Renewable Energies Focus (Yes/No)
• Other focus (Art, Forest and agricultural areas, etc.)
• Further information (Date of entry creation, last check and last update)

Values may be missing if some data points are not publicly available. The “largest single-family offices” are defined by the wealthiest families from New York who actively invest through investment vehicles and for whom reliable information is available. With regular, free updates and extensions, we constantly improve the data quality. 

New York City is the „single-family office capital“

New York City is one of the world’s most important financial centers, and also the American “single family office” capital. More than 80 major family investment firms are located in the city on the East Coast. Most single-family offices are located in Manhattan’s skyscrapers.

Home of America’s billionaires – and their family investment firms

No other American city hosts more billionaires than New York. Famous people like hedge fund billionaire George Soros, media mogul Michael Bloomberg, or industrialist Robert Koch live in NY. The high density of investment firms and banks, talents in the financial industry, and the high quality of living make it easy for many families to set up a family office in the city.

The financial sector with key importance for single-family offices

Interestingly, many billionaires who set up their single-family office in New York earned their fortune also in the city’s financial industry. Often, hedge fund founders turn their well-developed funds after several years into family investment vehicles. The best example of this is the famous mathematician and hedge fund founder Jim Simons.

Real estate investments of NY family offices

New York is known for its skyrocketing real estate prices and stunning real estate projects. For example, Google acquired the famous Chelsea Market building in Manhattan for $2.4B. Another interesting project is the Hudson Yards development in Chelsea, which was also financed by many major single-family offices. New York’s family investment firms are heavily involved in the real estate industry. For instance, a family office from 38th Street is the owner of many major NY hotels and is actively investing in new properties.

Family investment firms as investors in private equity and venture capital funds

Besides many different investment banks, private equity and venture capital firms play a huge role in NY’s business world. Out of the world’s five largest private equity firms, three have their headquarters in New York (Kohlberg Kravis Roberts, Blackstone Group, Apollo Global Management). Many family offices from Manhattan invest directly in private equity deals, as well as in relevant funds. The vibrant startup ecosystem of the city leads to an increasing number of NY single-family offices that also invest in venture capital deals.

Picture Sources: Priyanka Puvvada; Thomas Habr; Philipp Henzler via Unsplash