Why is this going up - relatively a big move, today?
I honestly don't know.
That is not important. The important thing is, you don't know either. Imagine, there is a long and there is a short watching now.
What will the long do? He will probably hold on. The guess is, somebody inside knows and he is acting on it.
What will the short do? She is confused. The business model is dead - at least that's what she has been telling people 8 hours a day, 7 days a week. Why would anyone want to touch this stock. Confused. She would either do a partial cover, or hold on. For the part of her that does cover, it would just feed on to the up move. Soon enough, other shorts are forced to cover.
As long as the price is still within reasonable range, this will repeat. Not everyday but every other couple days. IF there is a deal, $18 is not an out-of-the-question deal price.
For JCP, Ackman holds 20% of the company stock. Ackman is a speaker at an investor conference later today. My wide guess is, he is buying JCP in order not to look too bad in front of other people today. He has lost just about 50% on this JCP investment.