Historically, ETH and ETC move together, but one usually steals the show. You can see their movements are pretty well correlated but one is always significantly magnified compared to the other. Recently (the passed month) ETH has been pumping and ETC has been tightening in on support levels. Right now ETH is hitting a pretty big resistance zone so I think it might correct, give ETC a chance at a quick ~30%. I wouldn't hold ETC passed that though because come 2018 institutional investors will be more inclined to buy ETH over ETC due to fundamental analysis.