IMHO they are playing a big part with this dip because their celebration of New Year is about to come so basically people who has crypto wealth are starting to convert and release the cash in their wallets.
It's the whole world that is in down trend just like the stocks market. I don't have that much information of the whole reason why the separate markets are swimming into the bloody sea. Its not only the crypto world who is in crisis now but the whole world's market.