In 1970 Soros founded Soros Fund Management and became its chairman. Among those who held senior positions there at various times were Jim Rogers, Stanley Druckenmiller, Mark Schwartz, Keith Anderson, and Soros' two sons. In 1973, due to perceived conflicts of interest limiting his ability to run the two funds, Soros resigned from the management of the Double Eagle Fund. He then established the Soros Fund and gave investors in the Double Eagle Fund the option of transferring to that or staying with Arnhold and S. Bleichroeder.
It was later renamed as the Quantum Fund, named after the physical theory of quantum mechanics. By that time the value of the fund had grown to $12m, only a small proportion of which was Soros' own money. He and Jim Rogers reinvested their returns from the fund, and also a large part of their 20% performance fees, thereby expanding their stake.
By 1981 the fund had grown to $400m, and then a 22% loss in that year and substantial redemptions by some of the investors reduced it to $200m.
In July 2011 Soros announced that he had returned funds from outside investors' money (valued at $1 billion) and instead invested funds from his $24.5 billion family fortune, due to changes in U.S. Securities and Exchange Commission disclosure rules, which he felt would compromise his duties of confidentiality to his investors. The fund had at that time averaged over 20% per year compound returns.
In 2013 the Quantum Fund made $5.5 billion, making it again the most successful hedge fund in history. Since its inception in 1973, the fund has generated $40 billion.
The fund announced in 2015 that it would inject $300 million to help finance the expansion of Fen Hotels, an Argentine hotel company. The funds will develop 5,000 rooms over the next three years throughout various Latin American countries.