Germany sells first ever bonds with negative interest rates

Germany issued a 10-year bond at a negative interest for the first time on Wednesday, selling more than €4.0 billion with a yield of minus 0.05 percent, the German central bank or Bundesbank said.

Why would anyone buy a bond with negative returns when he can just keep cash?
Whole central banking is turning senseless.

First theory is central banks will buy back their bonds before expiry to push down interest rates….allowing bond buyers to exit at a profit.

Europe is in deflation, so say price of my penthouse I bought in London was $10million in early 2016…but at the end of 2017, it becomes $8million . With Brexit, it could be worse ,,,maybe less than half price like $3million !!!!
If I have cash of $10million, I will not park it in the guniang lose money London penthouse.
I cannot park it in the banks as well due to negative rates.
So, $10million is not a lot but IT IS STILL MONEY, correct ? I cannot put it under my bed.
So…conclusion, I buy bonds at $10million early 2016, get back $9.95million at the end of 2017. At least it is a contract, so the outcome is definite.,,I know I will get back $9.95milloon..It is really about risk assessment.

http://www.thelocal.de/20160713/germany-makes-investors-pay-interest-on-bonds