To my mind it won't come under 650$, I think this time it's price won't be so changable like it was this summer after bitfinex hack. Also now there are many factors to think like that, mining won't be profitable with low prices which automatically means price rise because more and more people are interested in bitcoin and many famouse companies like starbucks and etc are adding bitcoin as a new payment system, so while number or bitcoin customers are growing, it means more use of bitcoin, if there aren't so many bitcoins, this means price rise up.
Same here its impossible that the price will touch again to $650. i believe that the price can stay in 800 level and will increase this coming april or may.. this is just my own speculation and i think the price can stay long more in 800 level.
We are seen that the price was decrease right i think it is just because of panic sell just like old happen before..