Billionaire Bill Ackman donates £300m to brain research centre after daughter suffers haemorrhage

American billionaire Bill Ackman will donate $400m to brain research after his daughter suffered a haemorrhage that left her in a coma.

The investor, whose Perishing Square hedge fund is one of the most famous investment management firms in the world, announced plans to donate the vast sum to a newly established research institute named after him and his wife, Neri Oxman.

Ackman’s daughter Lucy suffered a stroke earlier this year that has left her unable to speak, see or walk. In a lengthy post on X, the financier described how his daughter was discovered unconscious in her New York apartment, and that when the emergency services arrived “they did not know what was wrong” with her.

Doctors eventually did a scan of Lucy’s brain to discover a “massive” haemorrhage, Ackman wrote to his 3m social media followers, which was later removed during a lengthy surgery.

The hedge fund billionaire and his wife established the Ackman Oxman Institute (AOI) in the wake of the ordeal. The Manhattan-based non-profit research centre will be devoted to becoming “the world’s greatest brain research, rehabilitation, recovery, human optimisation and longevity institute,” Ackman said.

The institute will be located in New York and focus on patient-related outcomes rather than academia, paper and research-related breakthroughs. It will be based in a 400,000 square foot building in Manhattan, part of which is set to be the repurposed studios that currently host Saturday Night Live.

The move represents one of the largest single philanthropic donations of the year. In 2025, British hedge fund manager Chris Hohn gave a record £1.4bn via his Children’s Investment Fund Foundation last year, according to The Sunday Times’ Giving List. Jeff Bezos’s ex-wife MacKenzie Scott has continued to release billions of pounds to good causes from the settlement of her divorce from the Amazon founder.

Ackman’s non-profit to have ‘commercial instincts’

Ackman’s donation will be made in the form of 10m shares in his New York-listed Perishing Square hedge fund, which were worth roughly $400m (£292m) at Thursday’s closing price.

Ackman is worth an estimated $8bn according to Bloomberg’s billionaires index, and shot to prominence with a $1bn short of American weight-loss supplement maker Herbalife. The financier branded the firm a pyramid scheme, and launched a vicious publicity campaign to convince regulators to launch a formal investigation.

The drive was ultimately unsuccessful, but it made the hedge fund one of the most famous investment shops on Wall Street. He has since become an avid supporter of Donald Trump, and – alongside Elon Musk – was one of his most outspoken supporters from the world of business and finance.

Ackman said the AOI will have “highly commercial instincts” despite its non-profit status, boasting a venture capital arm that will provide seed funding and then spin out any treatments and medications it develops.

“The advance of AI in the last few years will also enable us to greatly accelerate our mission,” he added. “AI still has a lot to learn about human intelligence and the brain, and the AOI should be at the forefront of the interplay between the brain and AI.”