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 Peabody Energy Corporation (NYSE:BTU) fell as much as 10% today after the company reported an even bigger loss than investors expected.

So what: First-quarter revenue dropped 5.5% to $1.54 billion and net loss more than tripled to $176.6 million, or $0.62 per share. The loss was far worse than the $0.32 per-share loss that analysts expected, and conditions don't appear to be getting better anytime soon.  

Guidance for 2015 was lowered to 180 million-190 million tons of sales volume in the U.S., 10 million tons lower than prior guidance.

Now what: Any hope for a turnaround in demand or profits was shot down today, and it looks like losses in 2015 will be even larger than anyone expected. Given the struggles the coal industry is having competing against natural gas, wind, and solar, I just don't see any reason for a rebound. As I wrote earlier this month, coal is dead and it's time for investors to move on to better opportunities in energy.