Willett Advisors
Michael Bloomberg's Single Family Office · New York, New York
$12B estimated AUM
15 contacts at Willett Advisors
Names & contact details for subscribers- Chairman and Chief Executive Officer
- Managing Director, Private Equity
- Managing Director, Portfolio Management & Due Diligence
- Managing Director
- Managing Director, Principal Investing
- + 10 more contacts
AUM figures are estimates compiled from public sources. How we source our data.
About Willett Advisors
Willett Advisors is the New York-based single family office of Michael Bloomberg, owner of Bloomberg L.P. and former mayor of New York City. In addition to managing Bloomberg's personal capital, the firm oversees the endowment assets of Bloomberg Philanthropies. It is led by Steven Rattner, a co-founder of Quadrangle. Third-party estimates place assets under management at approximately $12 billion.
Explore more of the largest single family offices.
Family office research
All articles- Exchange Funds vs. 351 ETFs: How Founder Families Diversify Without a Tax BillHow Section 721 exchange funds, Section 351 ETF seeding, charitable remainder trusts and direct indexing let founder families diversify concentrated stock, and what the IRS's September 2026 guidance changes for advisers.21 min read
- The SEC Family Office Exclusion After Archegos: What Family Offices Still DiscloseWhat Rule 202(a)(11)(G)-1 exempts and what it does not: 13F, 13D/13G after the 2023 amendments, Section 16, Form 13H, Form PF, Form SHO and withdrawn swap reporting, with Archegos as the case study.20 min read
- Raising Capital from Single Family Offices: A Field Guide for Alternatives ManagersHow single family offices actually decide, how they differ from endowments and RIAs as LPs, the Reg D, accredited investor, broker-dealer and marketing rule guardrails, and a step-by-step research and outreach process.20 min read
Frequently Asked Questions
What is Willett Advisors?
Willett Advisors is a single family office associated with Michael Bloomberg, based in New York, New York.
Where is Willett Advisors located?
Willett Advisors is based in New York, New York.
How much does Willett Advisors manage?
Willett Advisors is estimated to oversee approximately $12B in assets. As a private family office it files no public AUM disclosures, so figures are third-party estimates compiled from public sources.