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 medical imaging systems specialist Hologic (HOLX -0.23%) sank 15% today after its quarterly results and outlook disappointed Wall Street.

So what: The stock has been volatile in 2013 on doubts over management's strategic direction, and today's fourth-quarter results -- loss of $1.1 billion on a revenue increase of just 6% -- coupled with downbeat guidance only reinforce that skepticism. While the loss was mainly due to a one-time impairment related to its diagnostics segment, results were also affected by continued shortfalls in its ThinPrep Pap test line, suggesting that management may have to sell some assets to reignite growth. 

Now what: Management now sees 2014 adjusted EPS of $1.32-1.38 on revenue of $2.425 billion-$2.475 billion, well below Wall Street's view of $1.64 and $2.59 billion, respectively.

"We expect fiscal 2014 to be a transitional year for the Company and we remain confident the changes we are making to enhance the organization, combined with improving trends across our portfolio of market-leading products, will drive stronger financial performance in fiscal 2015 and beyond," said President and CEO Jack Cumming.

More important, with Hologic shares now off about 20% from its 52-week highs and trading at a forward P/E around 10, Mr. Market might finally be offering a decent opportunity to buy into those long-term prospects.