So far, Glencore’s gamble appears to be paying off. High demand from Asia helped thermal coal prices delivered from Newcastle, Australia, the world’s largest coal-export port, more than double since it bottomed in early 2016 to about $110 a metric ton. Export prices from South Africa and import prices into Europe are also at or near their highest levels in years. Glencore stock has struggled this year amid regulatory scrutiny linked to businesses in Africa and Venezuela. But its coal division was a big driver in the record earnings it recorded in the first half of 2018, generating more than a quarter of the $8.3 billion in earnings before interest, taxes, depreciation and amortization. Even after the recent weakness, Glencore shares have still more than quadrupled since the 2016 low in coal prices. Shares of global miners Rio Tinto PLC and BHP Billiton Ltd. doubled over the same period. […]