One value-focused hedge fund just doubled down on one of North America’s biggest coal exporters — here’s what that could mean for the stock’s next chapter.New York City-based Summit Street Capital Management increased its stake in Core Natural Resources (CNR +0.83%) by 81,170 shares in the third quarter, adding approximately $10.4 million in position value, according to a November 14 SEC filing.What HappenedSummit Street Capital Management disclosed in a November 14 SEC filing that it bought an additional 8 ...