We all know that all these crypto currencies are completely volatile in nature and therefore their valuation keeps on flactuation and varies according to market demand and supply and some flactuation in valuation is also contributed by the kind of investment so it is very obvious that higher the number of investors and higher the amount they are investing in crypto, higher will be demand and higher will be the valuation and after the December pump, there are lots of people who sold their coin resulting in decrease in demand and the crash in bitcoin valuation.