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 oilfield service company RPC (NYSE:RES) lost 12% of their value today after the company reported earnings.

So what: Revenue dropped 15% in the first quarter to $425.8 million, well below the $470.1 million estimate. Net income dropped 57% to $35.1 million, or $0.16 per share, and analysts expected a $0.25-per-share profit.  

Now what: Management pointed to strong competition as the reason revenue and earnings have fallen over the past year. Long-term contracts are also expiring, forcing the company to compete in the spot market. The oilfield service business is under a lot of pressure right now and I'd simply stay away from this volatile space.

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This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.