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 heart device maker Thoratec Corporation (UNKNOWN:THOR.DL) popped 10% today after its quarterly results and outlook impressed Wall Street.

So what: The stock has slumped in 2013 on dropping earnings and revenue, but a wide Q2 beat -- adjusted EPS of $0.52 on revenue of $130.5 million versus the consensus of $0.43 and $121 million, respectively -- coupled with upbeat guidance suggests that demand is starting to turn. In fact, sales of its HeartMate pumps climbed 9% on stronger-than-expected international growth, giving analysts plenty of good vibes over the device's global adoption rate going forward.  

Now what: Management now sees full-year EPS of $1.69-$1.79 on revenue of $490 million-$510 million, versus Wall Street's view of $1.73 and $494.2 million, respectively.

"HeartMate II has set a new standard for clinical performance and has facilitated broader adoption of VAD therapy," said CEO Gary Burbach. "We remain committed to continuing to drive the field forward through our significant investments in market and product development."

More important, with the stock still off its December highs and trading at a forward P/E below 20, there might be some room left to benefit from those prospects.