The bond insurers cover only the most senior tranche, which is the safest one.

FORBES: Buy Some Insurance

The three junior tranches would all have to be erased before the senior tranche's insurer loses money.

FORBES: Buy Some Insurance

Should a senior tranche default, the insurer has the right to step in and make the missing interest payments to forestall a liquidation.

FORBES: Buy Some Insurance

In the spring he paid between 70 cents and 80 cents per dollar of face value for a senior tranche of the WaMu Mortgage Pass-Through 2005-AR2, which carries a coupon rate of Libor plus 31 basis points, or 3.52% in September.

FORBES: Yes, there is a market for toxic mortgages.

The two owners would open this tranche of senior debt to other investors for equity warrants.

WSJ: Review & Outlook: The Solyndra Memorial Tax Break

Then there comes a whole tranche of corporate sponsored activity that teeters on the brink of lobbying: conferences with senior EU officials as speakers, but which are organised on behalf of big sponsors who send executives to mingle and meet the right contacts.

ECONOMIST: European politics