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?
Just like the current currencies, it is affected by such things listed above. Since, bitcoin is also a currency, but in digital form, it also exhibits the same idea to what it affects. Government, politics, trendings, competitprs were some of if. Every factors that could be listed can affect any currency in a small amount.
The events on the crypto market and the exchanges affect it a lot. The activities of the whales can sufficiently change the price of Bitcoin. Demand and supply are also very important.