Well, the Moody's shoe has dropped.

The rating agency just said it had put the U.S. on review for a possible downgrade, because of the interminable debt-ceiling debate.

Treasurys aren't reacting much, surprisingly: The 10-year is at 2.90%, just a little above where it was at the close. The Treasury Department is likely grateful Moody's at least waited until after a successful 10-year note auction to drop this news, though it is also hardly unexpected. It might make tomorrow's 30-year bond auction a little tougher -- unless this leads to a flight to safety that encourages investors to buy longer-term Treasury debt that's not subject to immediate default.

The dollar is down, with the euro at $1.42.

Full note after the break: