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 aerospace company Spirit AeroSystems Holdings (NYSE:SPR) sank 17% today after its quarterly results and outlook missed Wall Street expectations.

So what: The stock has soared over the past year on a string of better than expected quarters, but today's Q4 results -- loss of $586.9 million on a revenue increase of 4.8% -- coupled with downbeat guidance is forcing Mr. Market to sober up. Management cited charges related to the 787 program, as well as the establishment of a valuation allowance against deferred tax assets, for the big loss, triggering plenty of concern among investors over its bottom-line growth going forward.

Now what: Management now sees 2014 full-year EPS of $2.50-$2.65 on revenue of $6.5 billion-$6.7 billion, versus the consensus of $2.68 and $6.61 billion. "We're better positioned to move forward as we ramp up alongside our customers to all-time historical highs in commercial aircraft production rates," President and CEO Larry Lawson reassured investors. "We are entering 2014 with a strong cost discipline and relentless focus on performance and accountability that should begin to yield consistent cash generation." More important, with the stock now off 25% its 52-week highs and trading at a forward P/E of 10, Mr. Market might be offering a good chance to buy into that bullishness.