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.

Stocks wavered on Monday as the S&P 500 Index (^GSPC -0.75%) fell nearly 2 points, or 0.1%, on a day with light news. Although the S&P traded above 1,700 -- at all-time highs -- just weeks ago, it's been faltering since, and closed at 1,689 today.

While the S&P has been slowly losing ground, food-service distributor Sysco (SYY -0.76%) has been slumping more efficiently, losing 5.8% today to end at the bottom of the index. Misguided expectations were to blame: The company reported quarterly earnings today, and Wall Street wasn't impressed, despite posting higher-than-projected earnings. It was the profit decline that did it -- earnings per share fell from $0.54 a year ago to $0.47 per share in the most recent quarter.

Alexion Pharmaceuticals (ALXN), up nearly 300% in the last three years, stumbled 4.2% on Monday. Investors will have to wait until October 21 to hear the next quarter's results, so it wasn't a weak season of sales that hurt the company; biotechs were simply out of favor in the market. Though there wasn't a major catalyst behind the move today, some may be worried by CEO Bell Leonard's $24 million stock sale at the end of July, but investors should take solace in the fact that the top executive is still heavily aligned with shareholder interests, with more than $100 million in Alexion stock to his name. 

Finally, Air Products & Chemicals (APD) shed 3.3%, rounding out the daily list of laggards. The company, which sells atmospheric and specialty gases -- you can find many of its products on the periodic table of elements -- has a somewhat volatile sales history. Though it registered more than $10.4 billion in sales in 2008, it hasn't brought in that kind of business since, and sold just $9.6 billion of its wares in 2012.