Michael Burry ran a relatively nondescript hedge fund - until he realized that the US housing market was about to collapse and set about to profit from that.
(Remember, the market was overvalued, corrupt and unbalanced, and there is no ethical problem with benefiting from its implosion. Correction from corruption is part of the ecosystem. You don't want wasteful and unjust imbalances - like abnormally high housing prices - to persist.)
Made about $700 million that way.
Burry - one of the central characters of Michael Lewis's book The Big Short - has written a very interesting article here.
Read his take on what caused the crisis, how no-one noticed, what's next, and his view that our society still has not come to terms with an unresponsive elite class.