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 energy supplier Tesco (Nasdaq: TESO) fell 17% today after the company released earnings.

So what: During the third quarter, revenue grew 36% to $127 million, falling $2 million short of estimates. But the bottom line was much worse, and earnings of $0.10 per share fell well short of the $0.23 analysts had expected.

Now what: Management pointed to higher repair and maintenance costs, as well as costs to expand capacity, for the downfall. The earnings miss is concerning, but the growth Tesco is displaying should continue as drilling expands. I'm not jumping into shares because this is the fourth straight earnings miss for Tesco, but if shares continue to drop, they may be entering value range.

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