Have been observing this phenomenon for a while and am curious...

Have been observing this phenomenon for a while and am curious in any ideas why this should be the case.

Currently, NHC has a short interest of 5.25% whilst WHC is at 1.21%. Similar dependency on thermal coal prices and similar business characteristics, so this 'bet' on the NHC SP dropping vs no such expectations for WHC is interesting. The vast majority of the NHC shorts have been out of the money while for quite some time as well though I would also think many of those shorts are daily churns given the volatility of the coal prices and SP in general.

So my 2 theories are that either someone is waiting on an unfavourable decision on Acland or a hedge fund is implementing a pair trading strategy between NHC and WHC ie shorting NHC and going long on WHC for relative outperformance. Otherwise, it doesn't make a lot of sense that two companies trading at very low multiples whose valuations are 90% leveraged to the thermal coal price to have such a difference in short positions.