Rosenberg doesn’t think there is a bubble in U.S. Treasuries. Current low yields signal the aftermath of a credit bubble, deleveraging and deflation. He also wonders how there can be a bond bubble when it remains so widely detested.

“You look at the 10-year yields around the world and the U.S. is somewhere in the middle so it’s hard to say this is a full-blown bond bubble when there’s so much more to go,” added FusionIQ’s Ritholtz. “The U.S. is in the middle of bond yields for industrialized nations. You could get a lot less in yield.”

For example, German 10-year bunds are yielding about 1.5% and 10-year Japanese government bonds are yielding less than 1%.

In the U.S., low Treasury yields are “fair warning that the Fed is in the market impacting it,” Ritholtz added. “It’s a little bit of a warning the economy is slowing down.”

He also compared the Treasury market to the dot-com bubble in terms of investor psychology.

“If you’re honest with yourself, you have to admit bonds are going higher and yields are going lower,” Ritholtz told Bloomberg Television. “You have to admit it’s likely to end badly the way the dot-coms ended badly, and if you’re really honest you can admit you have no idea when the hell that’s going to happen.”

iShares Barclays 20+ Year Treasury Bond

Full disclosure: Tom Lydon’s clients own TLT.