Could be supply v demand, could be some smart cookie like Soros...

Could be supply v demand, could be some smart cookie like Soros has discovered an arbitrage play on the global scale that doesn't bite back.... Futures v current v short volumes? or a play on Copper financing?
who knows.

To add further to the big picture:

March futures are up, but doubt over longevity (after gold, brokers would be mad to be overconfident on bullish outlook):
http://www.cnbc.com/id/101288046

From Karvey commodity brokers 16Dec:

C'mon Wayno, get cash flows going while it's gangbusters on price, we all know mining is cyclic.....

I have a sense that we'll see a positive announcement next week (pure speculation on late fri volumes)....

hopefully it's not a nasty like this with Al:
Helpful in the short term, but longer term could bite....

http://www.nytimes.com/2013/07/21/business/a-shuffle-of-aluminum-but-to-banks-pure-gold.html?pagewanted=all