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) jumped as much as 20% in early trading today after the company released earnings.

So what: Second-quarter revenue rose slightly to $129 million and net income rose 16% to $10.2 million, or $0.26 per share. Analysts were only expecting $0.19 per share in earnings so the growth easily beat Wall Street's best guess.  

Now what: Slow North American demand continues to be a drag but the company is turning its focus to the international market where it's seeing success. I wouldn't expect strong growth over the next few quarters, but steady results should leave investors with a decent value right now. Shares trade at 13 times earnings and, with the bottom line improving, it's a good time to buy into an industry that should see growth in demand as energy prices rise.