What factors cause the fall in price of Bitcoin?
The only factor that causes price of Bitcoin to decrease is lack of demand. Supply is higher then is demand at the price that was in past so price drooped and supply and demand evened at lower price. No we wait that demand comes back so price moves o t higher level.
In my opinion the factor that cause fall in the price is only manipulation. Now small investors understand that big investors which we call whales will never let them make money from crypto investment. Therefore they are quitting which cause decrease in market cap and as there are no buyers in the market the demand is also low. In this situation the price will definitely fall.