Its fear... i wonder what happens when the NYSE opens in roughly 2 hours... So far its a bloodbath. Altcoins more than 50% loss since 3 weeks...

EDIT: Regarding Altcoins Investment: I think, similar to stock markets, the advice now is to look which company/foundation can actually survive another economic meltdown, aka recession or depression from now on and to invest in them. Whos CEO is actually capable of maneuvering his ideas and employees through such a troublesome time.
On a good side i think, we wont have 5000+ Altcoins after a few years anymore. It should clear up the field quite a bit...