Not sure but my guess it has been punters buying all the way down hoping for a quick upkick, It is only my opinion but I very much doubt PNA will get taken out, it isn't low enough on the opcost curve.
It's also an excellent leveraged punt on copper price as well. For every 10% the copper price goes up PNA should go up 20%. Reverse also holds hence the big selloff. Such is life for high cost producers.
