We're smack-dab in the middle of earnings season -- a time of year when you can be sure to see a lot of sudden movements in the market. Although the S&P 500 Index (SNPINDEX:^GSPC) added 7 points -- or 0.5% -- today, three of the 500 components distinguished themselves because of their poor performance on Monday, not their bullish movements.

The first of today's laggards, Alexion Pharmaceuticals (NASDAQ:ALXN), lost 2.3% just a few days before it's set to report quarterly earnings on Thursday. The $18 billion Alexion is primarily driven by the success of its Soliris drug, which treats a rare disease known as paroxysmal nocturnal hemoglobinuria. Behind the success of Soliris, Alexion revenues rose 45% in 2012. However, the company's business model is so one-dimensional that my colleague Sean Williams worries it will have to exceed estimates by at least 10% to maintain current price levels. 

One of the most successful innovators in the field of medical technology in recent years, Intuitive Surgical (NASDAQ:ISRG), saw shares drop 2% Monday. Investors continued to sell off shares in the company after last week's earnings report, which depicted unimpressive growth in surgeries performed by Intuitive Surgical's moneymaker, the da Vinci robot. Trading at about 28 times earnings, the 23% sales growth and 31% net income growth didn't quite meet expectations. 

The last of today's underperformers, Cognizant Technology Solutions (NASDAQ:CTSH), was mainly in the red because of fallout from another information technology mainstay IBM (NYSE: IBM). Cognizant doesn't report earnings until May 8, but the fact that IBM slipped more than 8% Friday -- its worst performance in more than eight years -- doesn't bode well for the health of the IT industry. Since Big Blue is still a nearly undisputed leader in IT, its disappointing results alone are enough to precipitate a drop in Cognizant shares.

Fool contributor John Divine has no position in any stocks mentioned. You can follow him on Twitter, @divinebizkid, and on Motley Fool CAPS, @TMFDivine.

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