Primus Guaranty Ltd's primary business operations are conducted through Primus Financial Products, which is one of the first credit derivative product companys. Basically, they insure major banks and financial institutions against risk on investment grade debt. Currently, the market is dominated by Primus and two other firms, but there are several more slated to begin operating in this market.
Since Primus is already established with a sterling reputation, these guys are set to capture a large portion of this market as more and more banks look to take some of the risk off their books. And since opening their doors in 2002, Primus has shown solid growth and profits, despite being one of the first in their field.
This isn't a risk free venture, since this is a new market they are liable to see themselves come under intense scrutiny and regulation by government bodies, but could pay off handsomely in the long run. If you have some risk capital laying around, this could be a good place to put it.