I've contacted a few friends who hold like me. They're all very concerned by the huge drop, but none has sold a single BTC.
We're all holders.
I know it's huge, but I believe the sharp fall in BTC's price has been caused by a very small number of individuals.
Waiting for data...
So i think the answer is clear mate and that is "The Whales" who is responsible for the dump ,but also some other small holders withdraw when the dumps starts badly.
like my friends none of us sold any small amount meaning many like us(small investors) who keeps their Bitcoin on hold but still the fall continues,though we are lucky now that we are seeing greens in market prices.