About Willett Advisors
Willett Advisors is a family office founded in 2010. It is primarily based out of New York City, United States. As of May 2026, Willett Advisors is an active investor, having invested in 16 companies, with 3 new investments in the last 12 months. It primarily invests in Series B round in United States based companies. Its investments are spread across a wide range of sectors from Life Sciences, Enterprise Applications. Its latest investment was a $257M Series D round in Cellares on Jan 28, 2026, which also saw participation from BlackRock and Eclipse.
Overall, Willett Advisors portfolio has seen 1 unicorn, 3 IPOs and 3 acquisitions including key companies like Circle, Formation Bio and Cellares. A lot of funds co-invest with Willett Advisors, with names like Fidelity Investments sharing a substantial percentage of its portfolio.
Willett Advisors has a team of 2 people including 1 partner.
Key Metrics
Founded Year
2010
Location
New York City, United States
Portfolio Companies
Sectors of Investment
Stages of Investment
Series B, Series C & 3 more
Locations of Investment
Unicorn in Portfolio
Willett Advisors' List of Top Investments
Willett Advisors has a portfolio of 16 companies, one of which is a Unicorn. Their most notable investments are in Circle and Finch Therapeutics.Their portfolio spans across United States, Italy and United Kingdom. They have invested in Life Sciences, Enterprise Applications, High Tech and 5 other sectors, across stages such as Series B, Series C and 3 more. Here is the list of top investments by Willett Advisors:1. Circle
Cross-border payment solution for businesses focusing on cryptocurrency. It offers a payments API for payment processing, a payouts API for global payouts solutions, and more. The mobile application is available for Android users.
Key facts about Circle
- Founded Year: 2013
- Location: Boston (United States)
- Stage: Public
- Total Funding till date: $1.5B
- Employee Count: 1,449 as on Apr 30, 2026
- Investors: Fidelity Investments, 2020 Ventures and 51 Others
- Latest Funding Round: Series E, Aug 22, 2023, $*****
- Highlight: Public
Provider of AI-powered drug discovery platform for various diseases. It leverages technology such as LLMs and the modern data stack in novel ways to efficiently design and operate clinical development in Atopic Dermatitis, Chronic Hand Eczema, and Knee Osteoarthritis.
Key facts about Formation Bio
- Founded Year: 2016
- Location: New York City (United States)
- Valuation: $*****
- Stage: Series D
- Total Funding till date: $608M
- Employee Count: 197 as on Apr 30, 2026
- Investors: ArrowMark Partners, Dragoneer Investment Group and 16 Others
- Latest Funding Round: Series D, May 21, 2024, $*****
- Highlight: Editors' Pick
3. Cellares
Manufacturer of a medical device for cell-based therapy. The company offers Cell Shuttle integrates all the technologies required for the entire manufacturing process in a flexible and high-throughput platform that delivers true walk-away, end-to-end automation. It also, offers software suite for cell therapy modalities.
Key facts about Cellares
- Founded Year: 2019
- Location: San Francisco (United States)
- Stage: Series D
- Total Funding till date: $612M
- Employee Count: 303 as on Apr 30, 2026
- Investors: Baillie Gifford, BlackRock and 16 Others
- Latest Funding Round: Series D, Jan 28, 2026, $*****
- Highlight: Editors' Pick
Developer of gene therapies using Adeno-Associated Viral vectors. It has two proprietary platforms leveraging DNA recombination and protein-intein fusion, to deliver large genes for various therapeutic applications. It offers two lead programs Usher syndrome type 1B associated with retinitis pigmentosa , using dual hybrid platform and for Stargardt disease, using AAV antgarde Intein-mediated platform.
Key facts about AAVantgarde Bio
- Founded Year: 2021
- Location: Milano (Italy)
- Stage: Series B
- Total Funding till date: $206M
- Employee Count: 70 as on Apr 30, 2026
- Investors: Amgen Business Development, Schroders Capital and 11 Others
- Latest Funding Round: Series B, Nov 03, 2025, $*****
- Highlight: Editors' Pick
Developer of cell-based therapies to treat intractable neurological diseases. It generate therapeutic compositions of a specific type of nerve cell (or neuron) for targeted delivery into the injured nervous system. It offers NRTX-1001, an inhibitory neuron therapy for epilepsy by GABAergic inhibition, reduce seizure activity, and repair the affected neural network.
Key facts about Neurona Therapeutics
- Founded Year: 2008
- Location: San Francisco (United States)
- Last Known Valuation: $*****
- Stage: Acquired
- Total Funding till date: $418M
- Employee Count: 110 as on Apr 30, 2026
- Investors: Fidelity Investments, Cormorant Asset Management and 15 Others
- Latest Funding Round: Series E, Mar 28, 2025, $*****
- Highlight: Acquired
Willett Advisors' Year-on-Year Investment Trends
Willett Advisors has invested in 16 companies over the last 8 years, with an average of 3 new investments annually in the last 5 years. In 2025, it made 2 investments, while as of Jan 2026, it has made 2 investments in this year. Its most recent first time investment was in Kinaset Therapeutics and most recent follow-on round was in Cellares.Year | No. of Investments | ||
|---|---|---|---|
1st Round | Follow-on | Total | |
2026 (YTD) | 1 | 1 | 2 |
2025 | 2 | 0 | 2 |
2024 | 3 | 0 | 3 |
2023 | 2 | 1 | 3 |
2022 | 2 | 0 | 2 |
2021 | 4 | 0 | 4 |
2020 | 0 | 1 | 1 |
2019 | 0 | 1 | 1 |
2018 | 2 | 0 | 2 |
Willett Advisors' Investments by Stage
Willett Advisors has made 7 investments in Series B stage with an average round size of $81M, 3 investments in Series C stage with an average round size of $187M, 2 investments in Series A stage with an average round size of $112M, 2 investments in Series D stage with an average round size of $127M and 2 investments in Series E stage with an average round size of $280M.Stage of entry | No. of Investments |
|---|---|
Series B | 7 |
Series C | 3 |
Series A | 2 |
Series D | 2 |
Series E | 2 |
Note: We have considered here, only first round of investments
Willett Advisors' Investments by Sector
Willett Advisors has a diverse portfolio, with companies operating in the Life Sciences, Enterprise Applications, High Tech, HealthTech and Artificial Intelligence - Industry Applications. Notably, it has invested in 16 Enterprise (B2B) companies, 15 Tech companies, 6 Software companies and at least 2 companies focusing on AI-Native.Sector | No. of Investments |
|---|---|
Life Sciences | 14 |
Enterprise Applications | 5 |
High Tech | 5 |
HealthTech | 2 |
Artificial Intelligence - Industry Applications | 1 |
Others | 7 |
Note: We have considered here, only first round of investments
Willett Advisors' Investments by Geography
Willett Advisors has made most investments in United States (14), followed by Italy where it has made 1 investment.Country | No. of Investments |
|---|---|
United States | 14 |
Italy | 1 |
United Kingdom | 1 |
Note: We have considered here, only first round of investments
Willett Advisors' recent investments
Willett Advisors has made 2 investments in 2026 so far - Cellares and Kinaset Therapeutics.Here are the most recent investments by Willett Advisors:
Filter this listDate | Company | Location | Round Details | Round Amount | Co-Investors |
|---|---|---|---|---|---|
Jan 28, 2026 | United States | Series D | 6257 | [+11] | |
Jan 12, 2026 | United States | Series B | 9277 | [+9] | |
Nov 03, 2025 | Italy | Series B | 9452 | [+11] | |
Jun 11, 2025 | United States | Series A | 3317 | [+9] | |
Nov 12, 2024 | United Kingdom | Series B | 5439 | [+1] |
Unicorns in Willett Advisors' Portfolio
Willett Advisors has 1 unicorn in its portfolio - Formation Bio. The most recent unicorn in their portfolio is Formation Bio which became a unicorn in 2021.Here is a list of unicorns in Willett Advisors' portfolio:
Tracxn Score | Company | Short Description | Founded year | Sector | Location | Company Stage | First Investment/ Acquisition Details |
|---|---|---|---|---|---|---|---|
70 | Provider of AI-powered drug discovery platform for various diseases | 2016 | New York City | Series D | czxei{c |
IPOs and Publicly Listed companies in Willett Advisors' Portfolio
3 of Willett Advisors' portfolio companies have become public. Circle got listed on the New York Stock Exchange (NYSE), in Jun 2025 at marketcap of $6.22B and Disc Medicine got listed on the National Association of Securities Dealers Automated Quotations (NASDAQ).Here are Willett Advisors' portfolio companies that went public:
Company | IPO Date | First Invested on | First Round of Investment | Round Size |
|---|---|---|---|---|
Jun 05, 2025 | May 28, 2021 | Series E | 5779 | |
Dec 29, 2022 | Sep 02, 2021 | Series B | 2183 | |
Mar 19, 2021 | Mar 01, 2018 | Series B | 6290 |
Acquired companies in Willett Advisors' Portfolio
3 companies from Willett Advisors' portfolio have been acquired. The most recent acquisition was Neurona Therapeutics in Apr 2026 by UCB for $*****.Here are Willett Advisors' portfolio companies that got acquired most recently:
Company | Acquisition Date | First Invested on | First Round of Investment | Round Size |
|---|---|---|---|---|
Apr 21, 2026 | Feb 06, 2024 | Series E | 7585 | |
Dec 09, 2025 | Nov 12, 2024 | Series B | 7418 | |
Dec 04, 2023 | Jul 26, 2022 | Series D | 1202 |
Team profile of Willett Advisors
Willett Advisors has a team of 2 members located in United States. Willett Advisors' team does not sit on the board of any company as of now.Co-investors of Willett Advisors
Over the past 8 years, 179 investors have co-invested in Willett Advisors's portfolio companies. This includes funds and angels.
- Invested before Willett Advisors: Atlas Venture, The Column Group and 62 others have invested in rounds before Willett Advisors. There are 5 companies where Atlas Venture has invested before Willett Advisors and 3 companies where The Column Group has invested before Willett Advisors.
- Top Co-investors of Willett Advisors: 75 investors entered a company along with Willett Advisors. These include investors like Fidelity Investments (2 companies).
- Invested after Willett Advisors: A total of 40 investors have invested in Willett Advisors's portfolio after their investments. Top Investors include BlackRock (2 companies) and Alameda Research (1 company).
Recent News related to Willett Advisors
•
Cellares Raises $257M to Fund Global Expansion, Eyes 2027 IPOEndpoints•Jan 28, 2026•Cellares, Eclipse, BlackRock, Eclipse and 8 others
•
EQT Life Sciences Backs Kinaset Therapeutics' USD103 Million Series BPR Newswire•Jan 12, 2026•Forge Life Science Partners, Kinaset Therapeutics, EQT, RA Capital Management and 8 others
•
Amgen Ventures joins $141M Series B for Italian gene therapy biotech AAVantgardeEndpoints•Nov 03, 2025•AAVantgarde Bio, Amgen, XGEN Venture, Neva SGR and 11 others
•
Antares Therapeutics Launches With $177 Million to Develop Precision Cancer MedicinesPulse 2.0•Jun 17, 2025•Antares, Omega Funds, Atlas Venture, Lightspeed Venture Partners and 7 others
•
•
Scorpion Therapeutics Raises $150 Million For Enhancing Clinical-Stage Precision Oncology PipelinePulse 2.0•Jul 28, 2024•Scorpion, Frazier Life Sciences, Lightspeed Venture Partners, Willett Advisors and 15 others
•
Scorpion raises $150M for next wave of targeted cancer therapiesEndPoints News•Jul 16, 2024•Scorpion, Frazier Life Sciences, Lightspeed Venture Partners, Willett Advisors and 18 others
•
Ysios Capital invests in Neurona Therapeutics' $120 million Series ECapital-Riesgo.es•Feb 09, 2024•Ysios Capital, Neurona Therapeutics, Viking Global Investors, Cormorant Asset Management and 15 others
•
•
Remix Therapeutics Closes $60M FinancingFinSMEs•Jan 03, 2024•Remix Therapeutics, The Column Group, Atlas Venture, Foresite Capital and 4 others
