Although we don't believe in timing the market or panicking over daily movements, we do like to keep an eye on market changes -- just in case they're material to our investing thesis.

Though some 62% of stocks lost ground today, indexes remained steady, and the S&P 500 Index (^GSPC 0.02%) still ended within 1% of its all-time high, reached just last week. It's the middle of earnings season, and while the broader market has maintained a fairly ho-hum attitude about results, individual stocks react with far more volatility. Though not all three of the S&P's three most notable laggards stumbled after earnings calls, the most pronounced loser was the victim of a poor quarter. The S&P, for its part, lost only about 5 points, or 0.3%, to end at 1,762. 

Logistics company Expeditors International of Washington (EXPD -0.18%) fell 6.2% Tuesday as earnings and revenue both fell short of expectations. Wall Street was looking for sales of $1.59 billion, but instead Expeditors International of Washington came in at $1.53 billion. Aside from missing on both top- and bottom-line numbers, this quarter shows that there's no hard and fast rule of thumb investors can use to predict future results. The third quarter's disappointment came as ocean carriers raised prices out of the blue, affecting margins in what Expeditors expects to be a temporary move.

Shares of the diversified electronics company Corning (GLW -0.03%), meanwhile, fell 4.4% as Apple closed a deal with GT Advanced Technologies to provide sapphire for the iPhone and iPad maker. Reading through the lines, investors feared that the agreement was a death knell for Corning's future as Apple's Gorilla Glass supplier, which is currently the material many Apple products use for their screens. Thankfully for Corning investors, the company has a diverse set of customers, and sells its wares to many of Apple's competitors as well. That said, Apple is an important account, and losing that business wouldn't work any wonders for Corning's business.

Lastly, shares of International Paper (IP 0.06%) lost 3.9%, despite no significant news to report for the day. In fact, the most significant news regarding International Paper came last week, when the company reported record third-quarter operating results and improved margins. Today's loss may simply be due to weak peer performance: Rock-Tenn, for instance, stumbled 8% today after disappointing revenue growth. Though International Paper's CEO sold some shares yesterday, it was an insubstantial amount -- less than 1% of his total holdings. Tuesday's fall shouldn't have much of an effect on long-term International Paper shareholders.