Some recent innovations, such as tradable pollution rights and catastrophe bonds, have provided a public benefit.

NEWYORKER: What Good Is Wall Street?

While Gulf Coast residents are just beginning to assess the catastrophic damage and coordinate relief efforts after Hurricane Katrina, there are already signs of one set of winners--investors in an arcane security known as catastrophe bonds.

FORBES: Magazine Article

Correlations between asset classes are appearing in unexpected ways, but are unlikely to reach holders of catastrophe bonds, the securities issued by insurance companies that pay tempting yields but can lose their value in the event of floods, earthquakes and the like.

ECONOMIST: Catastrophe bonds

"We have investors who want to buy, but no one on the other end that wants to sell, " said Judith Klugman, a managing director at Swiss Re Capital Markets, a unit of Swiss Re, which is both a major issuer of catastrophe bonds as well as a major market maker in the bonds.

FORBES: Catastrophe Bonds

For forty years, from 1941 when interest rates on 10 year bonds were 1.95% until 1981 when they peaked above 15%, owning bonds was a catastrophe.

FORBES: Bernanke, Buffett, Lappin: Bonds, Gold and Stocks