Willett Advisors LLC
Willett Advisors LLC is a private New York-based family office that manages the philanthropic assets of Michael R. Bloomberg, including Bloomberg Philanthropies, deploying capital across public markets, hedge funds, private equity, real assets, and direct investments.
- Company typePrivate
- Founded2010
- HeadquartersNew York, United States
- Headcount1–10
- GTM typeB2B
- OfferingServices
What Willett Advisors LLC does
Willett Advisors LLC is a private single-family office headquartered in New York that manages the philanthropic assets of Michael R. Bloomberg, including the assets of Bloomberg Philanthropies. Founded in 2010 and operating with a lean team of 1-10 employees, the firm employs a flexible investment approach aimed at long-term capital appreciation through a diversified portfolio. Its stated asset class coverage spans public markets, hedge funds, private equity and credit, real assets, and direct investments, executed both through selected third-party managers and direct positions — a structure typical of large endowments, foundations, and family offices.
The firm's go-to-market is structurally non-commercial: there is no external product offering, no fee schedule, no marketing beyond a corporate website, and no public revenue or AUM disclosure. Its investment activity is observed through disclosed direct-investment participation, most notably a co-investor role in Kinaset Therapeutics' $103 million oversubscribed Series B financing in January 2026 to advance frevecitinib, an inhaled pan-JAK inhibitor for severe asthma. Leadership is led by Chairman and CEO Steven Rattner, with Brian Allen as Managing Director of Private Equity and Olivia Ouyang as Managing Director.
Because Willett serves a single principal, there is no customer segmentation in the conventional sense and no disclosed pricing model. Revenue mechanics are not applicable in a fee-based sense; economic output is realized through investment performance on the philanthropic capital it stewards. The firm operates as an independently managed LLC with no disclosed parent company or institutional investors.
Willett Advisors LLC firmographics
Firmographics- Name
- Willett Advisors LLC
- Legal name
- Willett Advisors LLC
- Website
- https://willettadvisors.com
- Company type
- Private
- Founded year
- 2010
- Operating status
- Operating
- Headcount range
- 1–10 employees
- Short description
- Willett Advisors LLC is a private New York-based family office that manages the philanthropic assets of Michael R. Bloomberg, including Bloomberg Philanthropies, deploying capital across public markets, hedge funds, private equity, real assets, and direct investments.
- Ownership category
- akta.pro rank
Willett Advisors LLC industry classification
Industry- Product category
- Family Office Investment Management
- NAICS
- Portfolio Management and Investment Advice (52394), Portfolio Management and Investment Advice (523940)
- SIC
- Investment Advice (6282)
- akta.pro primary industry
- Portfolio Construction & Asset Allocation Advisory (FSAEAAAC)
- akta.pro secondary industry
- Real Estate Portfolio & Fund Management (Institutional/REIT/PE) (BPAJAMAJ)
Keywords
Where Willett Advisors LLC is headquartered
LocationHeadquarters
- HQ city
- New York
- HQ country
- United States
- HQ region
- North America
Offices1 record
Markets served
Willett Advisors LLC business model
Business model- GTM type
- B2B
- Offering type
- Services
Marketing channels1 record
Willett Advisors LLC product offering
Product offeringCore offering
Willett Advisors LLC manages the philanthropic assets of Michael R. Bloomberg, including the assets of Bloomberg Philanthropies. The firm pursues long-term capital appreciation by constructing a diversified investment portfolio, investing both through selected third-party managers and directly across a broad range of asset classes including public markets, hedge funds, private equity and credit, real assets, and direct investments.
Product overview
Willett Advisors LLC is a single family office entity that manages the philanthropic assets of Michael R. Bloomberg, including the assets of Bloomberg Philanthropies. The firm operates as a unified investment management organization rather than a product-based company. It employs a flexible approach to achieve long-term capital appreciation through a diversified investment portfolio, historically focusing on public markets, hedge funds, private equity and credit, real assets, and direct investments. The firm manages assets both through selected third-party managers and directly.
Differentiator
Problem solved
Functional benefit
Products and services
- Philanthropic Asset Management Discretionary investment management of the philanthropic assets of Michael R. Bloomberg, including the assets of Bloomberg Philanthropies. Delivered via a diversified portfolio across public markets, hedge funds, private equity and credit, real assets, and direct investments, executed through selected third-party managers and direct allocations.
Companies that use Willett Advisors LLC
Customer profileSegments1 record
Willett Advisors LLC technology and API
TechnologyTechnology focussed No
API detail
- Has API
- No
- API docs
- API detail
Core technology
AI maturity
App detail
Willett Advisors LLC partnerships and signals
Strategic signalScale indicators1 record
Recent moves1 record
Expansion highlights1 record
Willett Advisors LLC competitors and assessment
Company assessmentDirect peers
- Emerson Collective: Laurene Powell Jobs's family office/philanthropic vehicle pursuing mission-aligned direct investments across asset classes, blending philanthropy and principal capital allocation.
- BDT & MSD Partners: Advisory and merchant-banking firm serving founders and ultra-wealthy families with multi-asset strategies including direct investments — comparable in principal alignment and direct-deal participation.
- Rockefeller Capital Management: Multi-family office and wealth manager for ultra-high-net-worth families with diversified portfolio mandates — comparable in client base, scale, and advisory scope.
- Hillspire LLC: Jeff Bezos's family office, executing a diversified allocation across public and private markets for one principal — directly analogous in structure to Willett.
- Bessemer Trust: Multi-generational wealth advisor for ultra-high-net-worth families with multi-asset portfolio mandates — comparable in client profile and advisor role.
- Cambridge Associates: Endowment and foundation investment advisor running multi-asset portfolios for institutional-style principals — Willett's 'similar to endowments, foundations and family offices' framing maps directly.
- Iconiq Capital: Multi-family office and wealth manager to tech founders and executives with diversified multi-asset advisory mandates — strong peer for portfolio construction and direct-deal access.
- Soros Fund Management LLC: George Soros's family office investing across a broad, opportunistic multi-asset mandate — comparable in scale, flexibility, and principal-driven governance.
- Cascade Investment LLC: Bill Gates' investment vehicle — a single family office managing a diversified multi-asset portfolio for an ultra-high-net-worth principal, with comparable scope and flexibility.
Broad incumbents
- Angelo Gordon (TPG): Large alternative-investment manager running multi-strategy mandates including credit and real assets — overlaps with Willett's hedge, credit, and real-asset sleeve from an external manager perspective.
Market position
Strengths4 records
Weaknesses4 records
Competitive moat3 records
Key risks6 records
Key highlights6 records
Customer concentration
Willett Advisors LLC social profiles
Digital presenceWillett Advisors LLC financial estimates
Financial estimateRevenue estimate
Valuation estimate
Willett Advisors LLC leadership team
Management profileNumber of profiles
Willett Advisors LLC funding detail
Funding detailFunding overview
Funding rounds
Investors
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
Willett Advisors LLC M&A and investment
M&A and investmentM&A
Investments20 records
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about Willett Advisors LLC
What does Willett Advisors LLC do?
Willett Advisors LLC manages the philanthropic assets of Michael R. Bloomberg, including the assets of Bloomberg Philanthropies. The firm pursues long-term capital appreciation by constructing a diversified investment portfolio, investing both through selected third-party managers and directly across a broad range of asset classes including public markets, hedge funds, private equity and credit, real assets, and direct investments.
Is Willett Advisors LLC a public or private company?
Willett Advisors LLC is a private company. It is classified as family owned and is currently operating.
When was Willett Advisors LLC founded?
Willett Advisors LLC was founded in 2010. It employs 1 to 10 people.
Where is Willett Advisors LLC based?
Willett Advisors LLC is headquartered in New York, United States, in the North America region.
Who are Willett Advisors LLC's main competitors?
Direct peers on record are Emerson Collective, BDT & MSD Partners, Rockefeller Capital Management, Hillspire LLC, Bessemer Trust, Cambridge Associates, Iconiq Capital, Soros Fund Management LLC and Cascade Investment LLC. Angelo Gordon (TPG) is listed as a broad incumbent.
Does Willett Advisors LLC have an API?
No public API is recorded for Willett Advisors LLC.
What industry is Willett Advisors LLC in?
Willett Advisors LLC's product category is Family Office Investment Management. Its primary akta.pro industry code is FSAEAAAC, Portfolio Construction & Asset Allocation Advisory, with a secondary code of BPAJAMAJ, Real Estate Portfolio & Fund Management (Institutional/REIT/PE). Its NAICS code is 52394 and its SIC code is 6282.