system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Who "officially" keeps track of Bitcoin's value? How is it decided?
gpt
There is no "official" bitcoin price. There are lot of separate bitcoin marketlplaces (or bitcoin exchanges to be more precise) like Bitstamp for example. The price within one marketplace is decided by the buyers and sellers. If more people want to buy, the price goes up, and if more people want to sell, then it goes down. When you read somewhere that the bitcoin price is X, they usually either use the price in one of the bitcoin exchanges, or some sort of weighed average price between the biggest ones.