Mr. Nash, who fled Nazi Germany with his family at the age of 12, joined Oppenheimer as a trainee in 1951 when it was still a small Wall Street investment firm. He left briefly to work for his father’s textile business, but returned to the firm in 1954.
Mr. Nash became the company’s president in 1974, and its chairman in 1979.
At Oppenheimer Mr. Nash met Leon Levy, his longtime business partner. They specialized in leveraged buyouts and transformed the company into one of the world’s largest mutual fund businesses.
In 1982, Nash and Leon Levy sold the company for $163 million and invested $50 million of their own money to start the hedge fund Odyssey Partners. The partners settled into their complementary roles. Mr. Nash oversaw the fund’s short-term trades and negotiated deals, while Mr. Levy focused on longer-term investments.
Mr. Nash, who was also a founder of The New York Sun newspaper, was vice chairman of the board of the American Stock Exchange in the late 1970s.
Mr. Nash was born April 10, 1929, in Germany. He and his family immigrated to the United States at the beginning of World War II. He attended Stuyvesant High School in Manhattan and graduated from City College in 1953.
He and his wife, Helen Englander, donated millions of dollars to Jewish causes, as well as to other cultural and social institutions.
In addition to his wife, Mr. Nash is survived by his children, Joshua and Pamela, and six grandchildren.