While Wall Street was in ruin last year, John Paulson was laughing all the way to the bank thanks to his $20 billion bet against subprime and banks. Almost instantly, Paulson, who was something of a Wall Street unknown, became one of the richest men in hedge fund history.

Today, he continues to bet big. However, in a strategy shift he's actually buying banks now. Paulson this year has bought a significant stake in banks, including Bank of America, which he expects to nearly double by 2011, as well as Citigroup.

Paulson's other big gamble is less contrarian than those in the recent past. Even with gold reaching new highs on a daily basis, Paulson plans to open a gold fund in January 2010 and invest up to $250 million of his own fortune in it, as detailed in a recent Wall Street Journal article.

Already a major shareholder in miners AngloGold Ashanti and Kinross Gold, Paulson thinks there's plenty more money to be made in gold, according to our guest Gregory Zuckerman, author of “The Greatest Trade Ever”.

Zuckerman notes two primary reasons for Paulson's confidence in the trade:

1. Central banks around the globe have gone from sellers of gold to buyers, and that the global supply of gold is constrained.
2. The Federal Reserve will be very slow to raise interest rates and has dramatically increased the money supply. This of course will lead to inflation, another reason to be bullish on gold.

But with a net worth of about $6 billion, why is Paulson still looking for the next big trade? Why not just live the good life? "He's not like you or I, I don't think," Zuckerman says. "To John Paulson buying gold is the safe play."

Having already reaped the single-most profitable trade in Wall Street history, the odds suggest Paulson won't be as fortunate with gold. But I wouldn't want to bet against him.

What do you think? Will Paulson's latest scheme pay off, or is he pushing his luck?

VIDEO: http://finance.yahoo.com/tech-ticker/article/383273/Billionaire-John-Paulson%27s-Next-Big-Bet-Gold?tickers=GLD,GDX,BAC,ABX,AU,KGC,NEM