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 Federal-Mogul Corp. (NASDAQ:FDML) were sliding today, falling as much as 12% and finishing down 9% on a disappointing first-quarter earnings report.

So what: The auto-parts maker turned a per-share profit of $0.27 against expectations of $0.33, while sales missed expectations at $1.81 billion, increasing 7.2% to $1.78 billion. Despite the sell-off, the company saw a solid improvement from a year ago with net income from continuing operations more than doubling as co-CEO Daniel Ninivaggi said the manufacturer "continued to make progress strengthening our product portfolio and improving our cost structure."

Now what: European aftermarket sales remained weak, falling 3% as overall aftermarket sales rose just 0.8%. Still, its Powertrain segment saw sales improve 11%, beating broader market in Europe and North America where light vehicle sales improved just 3% and 4%, respectively. Taking the longer view, Federal-Mogul shares have wildly outperformed over the last year, up more than 200% even after today's slide, but this was the second straight earnings miss after series of strong beats so its days as a value play may be over. Carl Icahn is a majority shareholder, holding 81% of the company, so investors may want to pay attention to any moves he makes with the company, as that would likely guide shares up or down. 

Jeremy Bowman owns shares of Nike. The Motley Fool recommends BMW and Nike and owns shares of Nike. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.