The whole we don't invest in weapons, tobacco, coal, etc etc etc...

The whole we don't invest in weapons, tobacco, coal, etc etc etc is almost a religious thing proudly advertised by so many funds.
I think with the coal miners those funds had already all exited- and now with the high coal prices and absurd valuations the miners are bouncing back as less 'constrained' buyers at least are free to buy them.

It is hard to tell how much Aurizon falls into the 'sin stock' category , but given again the zeal for shunning certain sorts of companies it is probable that some funds are reducing their holdings because it hauls coal. The recent solid result and a bounce from the lows gives them an opportunity to do so.

For unconstrained investors this behaviour allows us to buy these assets at lower prices than normal and thus enjoy a higher yield. Even though the potential upside in share price is less than what it would otherwise be given the absence of many buyers.