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?
I am not sure but I think the biggest thing that influences the market value of Bitcoin is the demand. It is believed to be proportional such that what happens with the demand will be reflected to the market value of Bitcoin. Given that at this moment, the market price is continuously falling,chances are high that same thing happens with the demand. Surely, dumps are temporary. The market will soon recover so holding is advisable.