This huge price drops are because of the major manipulation happening in the market today. Also, these manipulations are being used by whales to take profits from small players and to maintain their dominance over the market.
I believe so too. If you look at what happened yesterday, many alts were in the double digits price appreciation, some like Nano even went up 50%. If you did some research you realised there was no big announcement, no key event, nothing.
It is believed that some bigger players use trading techniques that are illegal in other markets to manipulate the prices.