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 nutritional products company Martek Biosciences (Nasdaq: MATK) fell 10% today after the company released earnings and guidance.

So what: The latest quarter didn't turn out too bad, with revenue increasing to $119.1 million and adjusted earnings per share of $0.41, which topped estimates. What investors are focusing on is guidance for next quarter of $0.38 to $0.40 on revenue of $106 million to $110 million -- at the low side of expectations.

Now what: The market is handing out a drubbing after what looks like a very nice quarter. Guidance wasn't totally out of line, and considering the jump in sales, I think today provides a nice buying opportunity for investors. This Fool thinks that with Martek's forward price/earnings ratio of 13, there's plenty of upside potential for the company.

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