There are a lot of factors influencing the price of bitcoin, including technical issues/new alts coming out/regulations/stubborn miners/conflicts between developers(or groups)...etc.
What do you think is the most crucial cause? Why did the price drop dramatically these days? Will this be a rebound point?
if only the above issues I'm sure will not make the Bitcoin price go down like this, I pay more attention to its sales,
I think the investors are saturated with the market conditions like this,

so they make sales in the hope of re-buy Bitcoin in the price under.