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 miner Arch Coal (NYSE: ACI) jumped 24% today after the company reported second-quarter earnings that weren't as bad as expected.

So what: Revenue came in at $1.06 billion, well ahead of the $998 million target analysts had set. Loss per share on an adjusted basis was $0.10 -- also ahead of the $0.18 analysts thought the company would lose.

On a GAAP basis, however, the company lost $435.5 million, or $2.05 per share, as it took charges for closing some of its coal mines.

Now what: I guess investors are excited about results that are "less bad" than they were expecting, but I still don't see a lot to get excited about. Arch Coal is losing money and with the only bright spot in coal, metallurgical coal, the company reduced its sales expectations. I think this is a short-term bump, and I still don't like the direction the coal industry, or Arch Coal, is currently headed.

Interested in more info on Arch Coal? Add it to your watchlist by clicking here.