Tarrant died on Aug. 5 at his home in Bridgehampton, New York, his firm said, giving the cause of death as brain cancer.

Over 17 years, Tarrant turned Protege Partners into a powerful backer of small hedge funds, often identifying and seeding portfolios before they became widely known and successful. Protege was the biggest early investor with John Paulson's Credit Opportunities Fund that bet against subprime mortgages and earned Paulson & Co. $15 billion (£12.3 billion) in 2007.

"Jeff had a gift for thinking ahead of industry trends and had an irrepressible entrepreneurial spirit," said Ted Seides who co-founded Protege with Tarrant in 2001.

"From the first database for hedge funds, early seeding of managers and shorting credit and subprime before the financial crisis, to his most recent passion for machine learning, Jeff held forward-thinking original ideas and a drive to bring them to fruition," added Seides, who hosts Capital Allocators podcast.

News of his death generated an outpouring on social media and within the hedge fund industry with many sharing anecdotes of how Tarrant helped them.

Jeff "was keen to develop and support talent, then step back to let them stand on their own feet. May he rest in peace," Mohamed El-Erian, chief economic adviser at Allianz and former chief executive at Pacific Investment Management Co wrote on Twitter.

Two years ago Tarrant was diagnosed and treated for brain cancer. He stepped back from day-to-day management and moved into a newly created role of chairman, appointing Carol O'Donnell, who had been the firm's chief compliance officer, as chief executive officer.

At the height of the financial crisis, Tarrant and Seides in 2008 made a $1 million bet with Warren Buffett, long considered one of the world's most successful investors, that their basket of chosen hedge funds would outperform a Standard & Poor's 500 stock index fund over 10 years. They lost. Still Tarrant told the Financial Times in 2017 that he felt he had won given all the access he had to Buffett over the decade.

Tarrant graduated from Harvard Business School and co-managed the Sequoia Fund, a prominent portfolio, early in his career. He is survived by two daughters and two sisters.

(Reporting by Svea Herbst-Bayliss and additional reporting by Lawrence Delevingne in New York; Editing by David Gregorio)

By Svea Herbst-Bayliss