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 mobile-chip manufacturer Spreadtrum Communications (Nasdaq: SPRD) climbed as much as 12% today after JPMorgan upgraded the stock from overweight to positive.

So what: Along with the upgrade, JPMorgan increased its price target on the stock to $22, representing about 33% worth of upside to Friday's close. Spreadtrum shares have been bruised over the past six months on concerns over market share losses, but the Wall Street analyst cited a pair of recent TD smartphone design wins from giant China Mobile (NYSE: CHL) as potent catalysts for a turnaround.

Now what: Don't let today's pop keep you from looking into Spreadtrum. "We think a rerating is justified given that 1) its monthly smartphone chipset shipments should exceed 1MM units in 3Q12, and 2) new leadership at China Mobile is supportive of TD development," JPMorgan wrote in a research note to investors. More important, with Spreadtrum shares still off about 40% from its 52-week highs, there might even be room to buy into that bullishness.

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