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 power chip specialist Fairchild Semiconductor (NYSE: FCS) sank 10% today after its quarterly results and outlook missed Wall Street expectations.

So what: The stock has rebounded nicely over the past few months, but today's second-quarter miss -- EPS of $0.43-$0.45 versus previous guidance of $0.49-$0.54 -- coupled with downbeat guidance for the current quarter reignites worries over the headwinds facing management. Specifically, weak PC demand continues to weigh on sales amid the booming growth of tablets, forcing analysts to recalibrate their valuation estimates.

Now what: Management now sees third-quarter revenue of $355 million-$370 million, well below Wall Street's view of $388.2 million. "Mobile sales are expected to increase in the third quarter due largely to one major customer and continued growth from our Chinese customers," said Chairman and CEO Mark Thompson. "Our guidance reflects some conservatism given how difficult it has been for our customers to forecast actual mobile demand." With the stock now off about 20% from its 52-week highs and trading at a forward P/E of about 12, much of that uncertainty might already be baked into the valuation.