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?
Another reason maybe is the psychological factors which will lead to a misinterpretation of some issues or news around the world. Could be the negative issues that they heard about bitcoin.