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: Thoratec (Nasdaq: THOR) shares fell 10% briefly this morning after a company presentation and an analyst note.

So what: The company gave a presentation at the JP Morgan Healthcare Conference yesterday. While there wasn't any bad news, investors didn't walk away feeling impressed. After the presentation, JP Morgan reiterated its "neutral" rating and gave the stock a $30 price target.

Now what: Thoratec has steadied somewhat since it first hit our plunged list nearly two months ago. JP Morgan analysts may have said it best when they said there are "many irons in the fire, but they're all going to take a while to heat up." I wouldn't panic over this move today, but I will keep a close eye on advancements and slip-ups in the product pipeline going forward.

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