Prof Jayant Varma of IIM Ahmedabad has a nice post which gets to the crux of the negative interest rate issue.
He says as bonds have negative rates, the concept of yield/coupon etc is lost. So, investors are looking at bonds in terms of prices alone just like stocks. Whereas, investors are looking at stocks as bonds as they give dividends. So bonds are the new equities and equities are the new bonds.
This is like the prospect theory applying in monetary policy as risk averse bond investors are seeking risks in wake of losses:






