The currencies of the world are affected by many different parameters such as politics, economy, wars. The value of the money also shows up and down according to these parameters.
What are the parameters that affect bitcoin?
all of these can essentially affect bitcoin price too.
we have seen many times that economy has had its effect on bitcoin when people started investing their money in bitcoin to escape their country's bad economy.
but the biggest effect goes to adoption. since bitcoin is still a new technology as time passes and more people start to find out about bitcoin, put away their fear and use their brain to see the benefits of bitcoin they start buying it and with a limited supply price will go up.