Factors that influence the value of the bitcoin:
1) government bitcoin policies and laws
2) political situation
3) social trends
4) appearance of new competitors
5) artificial influence on the value by trading at the crypto market
6) news (not always true one)
and many more. Could be something new will appear in the future. Did I miss anything?
Oh yeah, i think also that things are also the factors that may affect the bitcoins value and how it goes up or goes down. First of all it's right that the factor may affects the value of bitcoin is the law and policies, why, because it regulates the supply and demand of the bitcoin and that's why we cannot be use it by ourself.