The following video is part of our "Motley Fool Conversations" series, in which consumer goods editor and analyst Austin Smith and software developer Chris Bledsoe discuss topics across the investing world.

In today's edition, Chris and Austin discuss the macro trend of sharply lower coal shipments in the railroad industry. Austin sees two main causes. First, we are coming off an unseasonably warm winter which reduces coal demand. Second, natural gas, an alternative to coal, continues to be incredibly cheap, which has depressed the demand for coal. Because coal makes up a large percentage of railroad companies' volumes, this has negative bottom line implications. Austin shares his thoughts in the video below.

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