My guess is that some of the whales dumped their coins quite suddenly and that caused a sudden collapse in the exchange rates. Actually, someone had posted proof for the same in the Bitcoin Discussion sub-forum.
It is very sad to see such a market, but definitely it is necessary to see a good trend.If the whales drop their coins, then most likely they are going to buy them in the future much cheaper.I think the real speculations and manipulations on the market are happening now. It is not worth panicking and selling all your savings at a reduced price.