Coal Fires Still Burn Despite Chill

Like other carbon-based energy sources, coal has gone from hot to cold lately.

Arch Coal, the No. 3 U.S. coal producer by market value, reports second-quarter results Friday. Analysts estimate its earnings per share more than doubled on soaring coal prices.

Coal futures on the New York Mercantile Exchange rose 71% during the quarter, roughly matching the stock-price gain for Arch and rival Peabody Energy, the biggest U.S. coal producer. Earlier this week, Peabody reported its profit doubled and said there wasn't enough coal on the market to meet global demand.

But July has been cruel for coal and the ...