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."

Interested in more info on Multi-Fineline Electronix? Add it to your watchlist by clicking here.

Fool contributor Evan Niu holds no position in any company mentioned. Click here to see his holdings and a short bio. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.