People are dumping bitcoins now and are starting to invest in altcoins. This is why we see the sudden change in altcoins prices. But I think it is just a matter of time before bitcoin's price recovers back again and reach a new ATH.
It's all normal. Bitcoin had its time to shine, which resulted in altcoins to stagnate, and even fall down, and now money is moving from one place to another. I am happy that the market is correcting a bit, because it just isn't healthy to see all time high after all time high gets broken through like it's nothing -- the market was simply said overheated. It was obvious that the price kept up just because of the looming chain split, and now it's clear that there won't be a chain split, a dropping price is the result. This is the reason I secure profits from time to time, because in these situations I benefit from the correction that was due for quite a while now.