PANs drop relative to the underlying nickel price could be explained by their costs. I haven't done the numbers but low cost operators will drop more in line with the underlying commodity whereas for a high cost operator a drop of 11% in the commodity price can mean the difference between the company being profitable (and therefore worth something) or not (and therefore worth nothing) - so you can get larger falls (and gains when the commodity in question goes up).
PAN Price at posting:
46.0¢ Sentiment: Hold Disclosure: Held