Hello!
How BTC's price change? What are the factors that affect the rise and fall of the BTC?
The amount of investors and supply and demand affects the bitcoin market greatly, specially since it is becoming a race until bitcoin reach its 21M cap. Ever since there is a worldwide need for online currencies and online transactions increase greatly it also affects bitcoins market chart.
Because of the demand of the people to use bitcoin and get it as an investment, you can see that the price of bitcoin is getting more expensive and soon we can easily see that the price of bitcoin will climb more because the supply of bitcoin is fixed and the demand is continue getting bigger and that will become the main cause for bitcoin to become one of the most expensive and it will also give a lot of profit or income to its investors or holders.