As a part of our continuing series. From CNBC

Germany sold 3.9 billion euros of six-month bills at a yield of -0.0122 percent on Monday, the first auction on record with a negative yield.

They go on

The result underscores the safe haven appeal of German debt in the midst of the European debt crisis continues. Negative yields indicate that investors are so nervous about protecting their money that they’re willing to essentially pay an interest rate to keep it safe.

This kind of phraseology irks me a bit as it makes it sound like the key issue is investor preference, but the underlying message is essentially correct.