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.
Really hard to pinpoint the exact value of Bitcoin if demand is our only basis for it, usually other assets such as stocks and real estate have other basis outside of demand to determine its real value or fair market value which Bitcoin as of the moment does not have. Many people (especially the new ones) think that what they are doing when they are buying Bitcoin is "investing" which is essentially not true as what you are really doing is trading as you are as of the moment basing your buying and selling decisions base on demand and its price charts, investing requires a lot of fundamental analysis which Bitcoin does not have.