Falling Treasury yields are a litmus test for pessimism, and there's plenty of that around.

Yields move counter to prices, and buying in the bond market has driven interest rates to a level not expected by many bond pros just several months ago. But the potential for bad news keeps piling up, and there are now expectations that the 10-year Treasury yield could touch 2 percent, or even the 1.87 percent it was at just before the election with another unexpected development.