The Credit Crisis Could Be Just Beginning

"Defaulting middle-class U.S. homeowners are blamed, but they are merely a pawn in the game," he says. "Those loans were invented so that hedge funds would have high-yield debt to buy."

The Liquidity Factory

Das' view sounds cynical, but it makes sense if you stop thinking about mortgages as a way for people to finance houses and think about them instead as a way for lenders to generate cash flow and to create collateral during an era of a flat interest rate curve.

Although subprime U.S. loans seem like small change in the context of the multitrillion-dollar debt market, it turns out that these high-yield instruments were an important part of the machine that Das calls the global "liquidity factory." Just like a small amount of gasoline can power an entire truck given the right combination of spark plugs, pistons and transmission, subprime loans became the fuel that underlies derivative securities that are many, many times their size.

Here's how it worked: In olden days, like 10 years ago, banks wrote and funded their own loans. In the new game, Das points out, banks "originate" loans, "warehouse" them on their balance sheets for a brief time, then "distribute" them to investors by packaging them into derivatives called collateralized debt obligations, or CDOs, and similar instruments. In this scheme, banks don't need to tie up as much capital, so they can put more money out on loan.