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 circuit protection device specialist Littelfuse (Nasdaq: LFUS) fizzled 12% Thursday after its quarterly results and guidance disappointed Wall Street.   

So what: Hurt by higher input costs and lower demand, Littelfuse posted second-quarter earnings of $25.3 million, or $1.11 per share, versus the average analyst estimate of $1.17 per share. "The strong momentum in sales and orders that we saw earlier in the year has slowed," said CEO Gordon Hunter. "Distribution channels have become more cautious and the electronics order rate has softened."

Now what: Expect the short-term pain to continue. Consistent with Hunter's bleak picture, Littelfuse now sees per-share earnings of $1.00 to $1.10 on revenue of $169 million to $177 million, while analysts were expecting a profit of $1.23 per share on sales of $182.7 million. Of course, with the stock now down 30% over the past three months and sporting a single-digit forward P/E, much of the risk might already be priced in.

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