The declining of negative interest rates of fiat money has a positive effect to the world of btc and altcoins. Why it is so? Because of negative interest rates it distresses the investors since the fiat is repeatedly lessen the value by the banks.

And the cryptocurrency and btc are not same with fiat, the crypto cannot be maneuver by anyone or anything for the reason that it is firmly day by day has limited output. No one can create more because it has limitations.
Also because the crypto is a trend today, I think more investors will choose crypto since it proposes supreme substitute for savings with indemand technology.