Here''s a financial instrument that's gaining fast; insurance against default on U.S. bonds

Are your U.S. Treasury bonds safe?

On its face, the probability of the U.S. defaulting on its spiraling debts seems highly unlikely. But that's not what the markets think. The price of insurance against such a default—using derivatives known as credit default swaps—has jumped by more than 50% in the private market in recent months. According to CMA DataVision in London, a specialist in these contracts, it will now cost you 0.34% of the principal per year to buy default insurance on U.S. government bonds. If you held $1 million in Treasurys, insuring against default would cost you $3,400 for the year. A few months back, insuring those bonds would've cost less than $2,000.