Shares in the biggest coal producers led the S&P 500 to one of its largest one-day falls since the summer, following Barack Obama’s re-election, as investors priced in the increased likelihood of the US President tightening up America's air pollution laws during his second term.

Shares in the US's largest coal producer Peabody Energy closed on Tuesday, election day, at $28.98. By the end of Wednesday the stock was down 9.6% at $26.24. An equity investor with a short interest in the stock borrowed at Tuesday's close of $28.98 and sold short at Wednesday's low of $26.06 would have made a notional gain per share of $2.92.