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?
I think the biggest factor bitcoin price fluctuation is government regulation and negatives news. Bitcoin still unregulated and many investors just speculate on bitcoin, its make bitcoin like pump and dump. If government regulation issued, I am believe investor will invest for long term because its good investment