The recent hysteria over negative interest rates has been hard to ignore.

As central banks around the world have abandoned plans to tighten monetary policy, bond yields have plunged below zero, meaning that investors are effectively paying for the privilege of lending to both countries and companies.

More than a quarter of the global bond market now carries a sub-zero yield. The trend reached a new peak — or nadir, depending on your perspective — on Wednesday, when Germany sold 30-year debt at a negative yield for the first time.


It is not just that the idea of a