Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of coal producer SunCoke Energy (SXC 0.85%) fell as much as 10% today after announcing its outlook for 2013.

So what: Management said coal sales are expected to increase slightly to 1.7 million tons next year but prices will affect profitability. Adjusted EBITDA is expected to be between $205 million and $230 million, with earnings per share coming in at $0.60 to $0.85. Right now, analyst estimates are for earnings of $1.26 per share.

Now what: This shouldn't be shocking news to investors, because coal prices have been dropping across the board. Metallurgical coal held up well until recently, but there continues to be pressure because of a slow economy around the world. I don't see this as a buying opportunity, and I'd be cautious about any coal-related stocks, thermal or metallurgical, going forward.

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