In 1985 the Quantum Fund was managing about $1.3 billion dollars and charging a 4% management fee. I know this because a good friend was just starting a career there that lasted a decade with Soros and Stanley Druckenmiller.
In any event, everything was going well until Soro's heir apparent and portfolio manager, Stanley Druckenmiller ( who came aboard in 1989 and engineered the big bet against the British Pound and Italian Lire) got involved in the momentum stocks in the late 90's ( Verisign at $220 comes to mind ). He actually attended a high-tech conference back in Idaho and started developing the thesis that "THIS TIME IT IS DIFFERENT"
As a result, the fund got caught invested in a lot of high growth, hi-tech, momentum type names ( including some huge bets in Biotech stocks ) that came crashing back to earth. The fund also got caught in some huge currency bets that turned sour, as well. The fund eventually closed down following the resignation of his top money managers, Stanley Druckenmiller and Nicholas Roditi in April of 2000. At the time, the Quantum Fund had suffered about $5 billion in losses in March of 2000 and was down to $8.5 billion in assets.
Up until that point Druckenmiller was +35% in 1999, exceeding the 21% advance of the S&P 500. The previous three years, Quantum's returns were lower than the S&P 500, and Druckenmiller's own record of 30% average annual returns between 1989 and 1999.
Soros then decided to turn Quantum back to a "conservatively" managed ENDOWMENT FUND in which they would aim for 15% returns instead of 30%, focusing in on less risky arbitrage and macro bets.
A few years later, in the Fall of 2001 George got the itch to start his hedge-fund business back up again and initiated a job search for a new President and CEO to run his fund again. William Stack, a former senior managing director and CIO for Dresdner RCM Global Investors where he oversaw a $60 billion portfolio became the new CEO for the new Quantum Fund.
Druckenmiller is currently ( and has been ) the President of Duquesne Capital, a multi-billion dollar hedge fund.