The average 10day volume in Alcoa is already beaten by 3 million shares in just 1-1/2 hours, and it's up 3.5%. (25M verses 28m already). The IO producers, along with most steel/copper/coal companies are all in the same downward mode today.
So, there is take over chatter and the stock is down? Next! You need to wake up with regards to the valuation of this company relative to any "take over" chatter and understand that this stock would be heading north if any of that were true.