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 Multi-Fineline Electronix (Nasdaq: MFLX) are short-circuiting today, with the stock plunging by 20% after the company reported earnings results last night.

So what: The circuit-board maker reported fourth-quarter revenue of $191.5 million, which turned into $0.18 in earnings per share. Both figures fell short of market expectations, which were for $200.5 million in sales and $0.34 in earnings per share.

Now what: Forward-looking guidance didn't look any better, with first-quarter sales expected between $200 million and $230 million, well below the consensus estimate of $231.7 million. The company was adversely affected by the flooding in Thailand, where it gets many of its components. Following the gloomy results, Needham & Company has downgraded the stock from "buy" to "hold," citing too many "near-term issues."

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