Why Mount Gibson, Newmont, Perenti, and Whitehaven Coal shares are dropping today

In afternoon trade, the S&P/ASX 200 Index (ASX: XJO) has given back its early gains and slipped into the red. At the time of writing, the benchmark index is down 0.1% to 9,021 points.

Four ASX shares that are falling more than most today are listed below. Here’s why…