I think one of the causes is the effect of trade war between China and America
and also the global economy is weak
It is very broad when it comes to the factors affecting bitcoin now, what you've said about the trade war between China and America might induce the influence to other traders to sell their bitcoin and to buy altcoins or even cashout. Massive events like these is just one of the factors that we can consider. But right now, we shouldn't be afraid, bakkt's being launched will be a big factor for bitcoin to bounce back and turn the table in its favor again.