Investment banker was a co-founder of hedge fund Odyssey Partners

Jack Nash, an investment banker who helped create the modern-day mutual fund and hedge fund businesses, has died. He was 79.

Nash died Wednesday at Mount Sinai Medical Center in New York, according to the New York Sun, the newspaper he helped found. A cause of death was not given.

His investment career began at Oppenheimer & Co., where he met Leon Levy, forming a partnership that would last decades and become legendary for its foresight and returns.

Nash, who became Oppenheimer’s president in 1974 and chairman in 1979, helped mold the firm into what once was the world’s second-largest mutual fund business.

After the pair sold the firm in 1982 for $163 million, they founded Odyssey Partners, putting $50 million of their own money into the fund.

“They were so far ahead of their time,” Michael Peltz, editor of Alpha magazine, said of Nash and Levy. “If you look at what they were doing in the 1980s, they were investing in public equity, private equity, activism, distressed, and doing it all under one roof. It was like a modern-day multi-strategy [fund] well before anyone had even come up with that name.”

Levy structured complex, long-term transactions, while Nash focused on short-term trading at Odyssey, which generated annualized returns of 22.4% over 15 years, according to Alpha, a hedge fund publication.

The two liquidated the business in 1997 when it had $3.3 billion under management. Levy died in 2003 at age 77.

“I learned a lot of what I know today from my brief tenure at Odyssey,” said John Paulson, founder of Paulson & Co., a New York-based hedge fund firm that oversees $33 billion. “They were really pioneers in the hedge fund format.”

Nash was born April 10, 1929, in Germany and immigrated to the United States with his family at the start of World War II.

He started work at Oppenheimer as a trainee in 1951 and returned in 1954 after working in his father’s textile business, according to a 1988 article in the New York Times. He graduated from City College of New York.

Forbes magazine estimated Nash’s net worth at $750 million in 2004, when it ranked him as the 389th wealthiest American.

Nash is survived by his wife, Helen; two children, Joshua and Pamela; and six grandchildren.