The price of any asset is set by buyers and sellers through supply and demand. Supply is how much is available for sale. Demand is how many people want to buy it. If there is more demand than supply, the price rises. If there is more supply than demand, the price falls. This mechanism is the foundation of every market in the world.
💡 Example
In summer, the price of flights rises because more people want to fly (high demand) than there are available seats (limited supply). In January, flights are cheaper because demand is lower and the same seats are available.