"I have made it a principle to pursue my self-interest in my business, subject to legal and ethical limitations, and to be guided by the public interest as a public intellectual and philanthropist," he wrote. "If the two are in conflict, the public interest ought to prevail," he said.

Soros opened his first foundation, the Open Society Fund, in 1979, when his fund had reached about $100 million and his personal wealth had climbed to about $25 million. His initial focus was on promoting democracy and a market economy in Eastern Europe. Soros now funds a network of foundations that operate in 70 countries around the globe, everywhere from the U.S. to Montenegro to South Africa and Haiti.

In late 1988, he hired Druckenmiller to be his chief strategist to take over the day-to-day trading of the firm's assets so he could concentrate on his charitable pursuits.

Breaking the BoE

While Druckenmiller was the architect of the $10 billion British pound trade, which forced the currency out of the European exchange-rate mechanism, Soros served as a coach to the younger man, encouraging him to increase his bet.

Druckenmiller left in 2000, together with another star manager, Nick Roditi, after losses when the technology bubble burst. Just two years before, the firm had been the biggest hedge fund in the world with $22 billion in assets, and Soros said it was too much money to manage in such concentrated positions.

After the departures, Soros decided to farm out more money to portfolio managers both inside and outside Soros Fund Management. He said he would settle for a 15 percent annualized return, about half of what the fund had posted since its start.

Stepping In

In 2007, as the subprime mortgage crisis was gaining speed, Soros again stepped in. Quantum returned 32 percent that year and posted an 8 percent gain in 2008, when funds on average dropped about 19 percent. Overall, Quantum Endowment grew from about $11 billion in June 2000 to today's level.

The firm went through several chief investment officers, including Soros's son Robert, before hiring Anderson, who was a co-founder at BlackRock Inc. and its global fixed-income chief.