It mostly related to what is going on in the stock market. There were major margin hikes everywhere on Friday, these margin hikes forced funds to trim holdings, trimming holdings meant selling some of their longs which included bitcoin now. If that deleveraging never happened, the price would likely have held a lot better than it did. If this deleveraging continues into next week, bitcoin will likely dip further. In the past deleveraging events like that were very short term events that were done in a day or a couple days. We shall see if this is more of the same.