So I know this is an absolutely crazy thing to say, but before you think about trading a commodity you probably want to know at least the very basic facts about it. And I'm talking actual facts, not what you're served up on Fox, Breitbart, and the Daily Caller. When you say "coal" what kind of coal are you talking about? Thermal coal or metallurgical coal? You do understand that those are two vastly different markets, right? You do understand that price of metallurgical coal is much higher than the price of thermal coal? And that price is based on demand, which is mainly based on the need for steel in the global economy? Versus thermal coal which is mainly used to generate power. And whose price is mainly based on the price of its substitutes, which mainly consists of natural gas? And you understand the economics of shipping thermal vs metallurgical coal? And of course the fact that even among those broad categories, there are vastly different types of coal of differing hardness, moisture content, sulfur and phosphorus content.... You do understand that a MWH of coal power is significantly more expensive than a MWH of natural gas produced power almost everywhere in the U.S., and would be even if there were absolutely no regulations on coal at all and we could go back to your "good old days" of acid rain, NOx, and particulate pollution?
If you're actually interested in investing in coal rather than overlaying your political views on the subject, then the TLDR answer is that thermal coal mines are done in the U.S., full stop, regardless of political party in power or your view on global warming or any other environmental issue. If you truly "don't pick winners and losers" then coal is a loser on price and every other aspect when it comes to power generation in the U.S. and will be almost entirely gone within 20 years absent the government forcing people to pay more for coal powered electricity than they would otherwise (as Trump contemplated doing with requiring rate-basing of coal plants but hasn't been able to pull off yet).
Metallurgical coal is going to be around for a long time, again regardless of political party in power. It has a remarkably high correlation with the global economy, so it will wax and wane as the global economy does. Even metallurgical coal is not very energy dense so there will always be supply chain aspects that make every mine highly idiosyncratic in how its fortunes respond to the economies of various parts of the world.
None of this is news to anyone who actually makes their living in this industry. Thus it's fully priced into the price of coal mines. If you're planning on trading coal spot, well again you probably need to do some research on the transportation and storage of coal along with the market fundamentals before you dive into that!
