The price of bitcoin is determined by supply and demand of the market. bitcoin is a decentralized currency so there is no central organization that determines its price.
I do agree. The price of Bitcoin adjust in terms of demand and supply so that means that the demand in Bitcoin is increasing because the price is rising and vice versa whil on the other hand the supply is limited unlike in centralized coins which you can release a particular amount so that the price would be stable as the demand increases likethe fiat system that we have.