Probably it is the upcoming halving. Just like the event of litecoin halving last year. It is normal. Bitcoin and altcoin's price movement are in the two directions.
This especially and the selling off of bitcoin in droves. It just hit $470 on my price ticker and should be $475 by morning if it keeps up like this.
I think it will keep going up, to hit 500$ and more. which mean I should get rid of my Altcoins and minimize my losses. and wait for the bitcoin rise to stabilize. then buy Altcoins when they are cheaper and wait for them to hit a high price.