Nothing makes negative interest rates impossible right now, in fact it is a reality in several countries. Obviously not something that is available to most bor

Nothing makes negative interest rates impossible right now, in fact it is a reality in several countries. Obviously not something that is available to most borrowers, but government bonds with negative nominal rates do exist, and even US treasury debt has negative real rates (i.e. accounting for inflation) for shorter duration notes/bills. Obviously there is a limit to how negative the rates can become -- eventually the market will find other places to invest -- but that would be equally true with digital currencies.