If no one spends bitcoin and no one buy it but many people are mining it expect for price decreases gradually because the supply is increasing daily..
And more supply will come..
The price of bitcoin is always depends in demand and supply.. if bitcoin is in demand expect for price of bitcoin to increase high..
yeah, the price would most probably be going down because people would just hold and not do anything with their bitcoins, that would be really bad in my opinion
I also think the price might decrease because if there is no bitcoin trading then the price won't increase. On the other hand if the people buy bitcoins more and more and just keep on holding them then it will be really bad for the market as it will negatively effect bitcoin market ! so we should use / spend bitcoin as much as we need rather holding !