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 you're right. There are several factors and it's quite hard to tell which is the most influencing one, but to me it is the trends in the society.