I guess the reason why bitcoin has a stable price is because miners are mining sometimes or even stop mining at all. The supply of coins freeze and the price would definitely freeze to. Correct me if im wrong but i really believe mining and the price are linked. If one stop moving then the other one will follow.
The price range of bitcoin seems to go on stable thos 2018 but I would like to believe that before the year close probably in the mid of November the price will soon rise again. The market seems to go an a stable and safe place this year but the bull didn't hit yet. I really feel something will happen in few months from now so I keep on holding and keep on investing if I could.
If demand is increasing it means that people are investing in the Bitcoin right now the value has declined so we take it as the demand rate has decreased. We will see many ups and downs in the value of Bitcoin due to change in demand rate or you can say demand and supply rule affect of price. If price gets stable then you must know that market support is strong and perfect right now which has made it stable.