It is no longer absurd to think that the nominal yield on U.S. Treasury securities could go negative. Last week the German 30-year government bond yield dipped into negative territory for the first time ever. Around $14 trillion of outstanding bonds worldwide, or 25% of the market, now trade at negative yields, according to Bloomberg. What was once viewed as a short-term aberration - that creditors are paying debtors for taking their money - has already become commonplace in developed markets outside of the U.S. Whenever the world economy next goes into hibernation, U.S. Treasuries