I think one of the factors that can affect the bitcoin price is bad news or FUD's that can holders sell their bitcoin because they think that the price of bitcoin will drop and the other factor is there are some group of a pump and dump that can manipulate the value of bitcoin and the other thing is there are many scammers out there that use bitcoin as their presentation that is why people didn't trust bitcoin because of this reason. 
Investor sentiment is unstable, bad news from the market and whales actively control the market in the direction they want to be, which makes the market and the value of Bitcoin much fluctuate. I hope that as the cryptocurrency market becomes stronger, this situation will no longer occur.