if no one is going to spend bitcoin,means there can't be any buyer which will make the market stable or market will go in ideal state where nothing is moving and graph will just be a straight line, which means the price of bitcoin will remain same,but it's never gonna happen because there will be someone who is going to sell bitcoin no matter what and keep the market moving .

on the other hand a second case can take place that is:
 price can go up because people expect that more people will expect that some people will buy,  or price can  go down  if everyone get bored of stable market ,and thus demand of btc could decrease .

 so in the long run where fundamentals matter, eventually holders will sell just because they need to buy things.