My analysis is the traders who are dumping are the same people who came in late. They thought that ETC will reach ETH parity in a short amount of time so the bought at any price available. The few clever ones dumped on the buyers early and took profit. When the majority realized this they too dumped taking small profits and some dumped resulting in losses.
The trade volume of the ETC is quite low at the moment. I think the big dump has not started yet so far.