As I posted a while back, I wouldn't be surprised to see cor show the same pattern this year as last: a rally on no news, and then a drop on no news.
There are always a few people who sell at year's end for tax purposes (even this year), and some of them will be buying back. Because of the very low volumes this stock trades at, this gives enough momentum to the stock that it attracts other buyers, mostly short-term, who sell on the pop.
Because BPs have so many options, a deal with cor is going to be very slow. I still think March is more realistic than January. I don't know if cor can make it much later than that.
My concern is that cor has to have a back-up plan if a deal can't be finalized before funds dry up. The terms of that back-up plan are likely to be ugly, and the funds raised may be inadequate.