Into my conscience there are so many questions why alts has to drop when btc drops. I mean if alts has their own good values then it should drop as well.
I think there are lots of threads created with the same question,so next time explore the forum before asking questions.
This is due to the panic selling of the coin holders when bitcoin price starts to fall.But there is no relationship between the price of bitcoin and altcoins the price will be depends on the supply and demand of everycoin.