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 oil and gas equipment small cap Newpark Resources (NYSE: NR) fell a staggering 30% in early trading Friday after the company posted worse-than-expected quarterly results.

So what: Although third-quarter profit soared to $8.2 million, or $0.09 a share, Newpark still missed the average analyst estimate of $0.11 a share for the period. Even more concerning to Wall Street is that weak demand for its ballyhooed water-based drilling systems led to a top-line miss: Sales for the quarter came in at $179.27 million versus analyst expectations of $187.51 million.

Now what: I don't know about you, but a one-day 30% haircut seems like harsh punishment for today's miss. While the report certainly comes as a short-term shock, the long-term picture for Newpark's fluids systems segment remains exciting to this Fool. Of course, given Newpark's small size and risky nature, I'd urge Fools to buy it in a basket with larger, dividend-paying energy service stocks like Schlumberger (NYSE: SLB), Halliburton (NYSE: HAL), and Baker Hughes (NYSE: BHI) -- all of which are also reasonably priced.

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