Hedge fund billionaire Bill Ackman commits $260 million to brain institute after daughter's hemorrhage

Bill Ackman's family foundation is committing $260 million to two buildings on Manhattan's Upper West Side to create a brain research institute, a project the hedge fund manager said was set in motion by his daughter's brain hemorrhage in February.

The Pershing Square Foundation closed on Tuesday on 125 West End Avenue, a 400,000-square-foot building between West 65th and 66th streets, paying $190 million. It has signed a contract for the adjoining property at 320 West 66th Street at $70 million. Combined with additional development rights the foundation is acquiring, the finished complex could approach 700,000 square feet, close to double the current footprint.

The centre will be called the Ackman Oxman Institute, after Ackman and his wife, the designer and researcher Neri Oxman. It is being developed in partnership with Mount Sinai and will house researchers working across genetics, nutrition, longevity and rehabilitation, with space set aside for neurosurgery.

A family emergency and a shelved plan

Ackman told Fortune, which first reported the transaction, that the decision followed a medical crisis. His 26-year-old daughter Lucy suffered a brain hemorrhage in February and was found lying alone on the floor of her apartment roughly 15 hours later. She has since improved significantly and is being treated at Mount Sinai.

The idea itself predates that. Ackman said he and Oxman had been weighing a major commitment to brain research since her mother died of Alzheimer's disease five years ago, and had looked at the same West End Avenue site at the time. The combined cost of the real estate and of staffing an institute made it unworkable. A downturn in the life sciences sector and a growing willingness among scientists to leave academia changed the arithmetic.

The foundation has been funding neuroscience for several years. It launched the MIND Prize in 2022 to back early and mid-career investigators working on cognitive health, modelled on the Pershing Square Sohn Cancer Research Alliance formed in 2013, which has committed more than $49 million across 77 scientists. Established in 2006 with Ackman and Oxman as co-trustees, the foundation has committed more than $930 million in grants and social investments. Its domestic giving concentrates on New York, while its international work has centred on Africa and Israel, according to philanthropy tracker Inside Philanthropy.

A building with several lives

The West End Avenue property currently houses West End Labs, a life sciences and research campus. It was originally constructed as a Chrysler parts and service facility, later formed part of the New York Times printing plant that once dominated that stretch of West End Avenue, and most recently held offices for ABC and Capital Cities. The structure escaped demolition earlier this decade and was converted for laboratory use.

Ackman's balance sheet

The commitment lands three months after Ackman took his firm public. Pershing Square Inc. and the closed-end fund Pershing Square USA began trading on the New York Stock Exchange on April 29 in a dual listing that raised about $5 billion, the largest closed-end fund offering in United States history, and a structure Ackman has described as a step toward a Berkshire Hathaway-style permanent capital base.

The debut disappointed. Pershing Square USA was priced at $50 a share, opened at $42 and traded near $41 on its first afternoon. The asset manager opened at $24 and slipped to about $22.50. Forbes valued Ackman at roughly $9 billion that day, ranking him 378th in the world.

Pershing Square managed $30.7 billion at the end of December, according to an April registration filing, and Ackman directly owns about 45 percent of the entity that runs its funds. He founded the firm in 2004 with $54 million after leading Gotham Partners from 1993 to 2003, and built his public profile through activist campaigns and a long, costly short position against Herbalife. His family office, Table Management, held about $2.25 billion outside Pershing Square as of mid-2024.

Ackman has lived on the Upper West Side for years. He sold an apartment in the Beresford on Central Park West in 2025 and holds a penthouse further uptown, for which he appeared repeatedly before the local community board in 2021 to win approval for a glass extension.

No opening date has been set for the institute. The second building has not yet closed, and the eventual scale of the complex depends on whether the foundation builds out the development rights attached to the site.