A gulf has opened up between Aurizon and the broader sharemarket as the rail haulage group’s investors become more pessimistic about future demand for Australian coal because of more countries slashing carbon emissions.

Aurizon’s shares, which have slid 30 per cent over the past 12 months to trade at $3.73, are now trading at their biggest gap to the broader Australian market since the company listed a decade ago, despite an ongoing stock buyback.