Not only crypto currency market dude. All the products in the world are determined the rate with the supply and demand theory only. So whenever the bitcoin supply is less when the time bitcoin is been used by the large number of people. In that time, bitcoin price will increase. This applicable for the both bitcoin and other altcoins too.
Next factor, adoption is the matter to pull the price to peak as it will increase the need of bitcoin supply in the crypto market. Difficulty chart in the coinmarketcap will explain you easily.