The value of bitcoin depend on a lot of things the most important one would be how much people know about it and invest in it and trust it a lot of people because we all here want to have some bitcoins and that is already a lot of people.
Basically, it is one of the factor why we saw bitcoin continously growing and pump, its actually not just because of its high demand but also becausebut gaining really great popularity at the same time. Well known personalities are actually getting involved with cryptosystem which maybe the reason why great number of people are trusting and getting themselves also involved with it.