Bitcoin has been used in illegal transactions, the large amount of electricity used by miners, price volatility, and thefts from exchanges. Some economists, including several Nobel laureates, have characterized it as a speculative bubble. Bitcoin has also been used as an investment, although several regulatory agencies have issued investor alerts about bitcoin
Bitcoin is traded on multiple exchanges all of which set their own average prices based on the trades being made by the exchanges at a given time.
If you want to buy and sell Bitcoin, you have to choose a particular exchange, which will have its average price. The price of Bitcoin fluctuates at any given moment, depending on which exchange the information comes from.
The Bitcoin market is influenced by many events.In some cases, the price can be driven down by large traders who sell bitcoins off in high volume.