I think at this point we can just ignore the yields on bonds. The majority of the "income" from government bonds has come from capital gains, not the coupon.

I think at this point we can just ignore the yields on bonds. The majority of the "income" from government bonds has come from capital gains, not the coupon. Then the yield decreases it is because the bond itself has become more expensive. Sell the bond at the higher price. Negative yield is an annual rate. Taking a short position is more expensive. Holding a CDS is more expensive. If you expect negative yields to continue or go deeper, then bonds are a good investment. Now, if you are in more illiquid corporate bonds, then you may be forced to hold them till maturity.