The stock market edged higher today, as investors applauded strong earnings, and home prices rose slightly more than expected in February. Broad gains in real estate prices within the past year have helped to solidify the economic recovery, while also making it far more difficult for average Americans to afford homes. But after a nine-month slump, pending home sales finally edged higher in March, showing that housing may be more affordable than investors thought. Alas, shares of Boston Scientific Corporation (NYSE:BSX), PACCAR (NASDAQ:PCAR), and Eaton Corporation (NYSE:ETN) were blind to the market's optimism, ending as three of the worst stocks in the S&P 500 Index (SNPINDEX:^GSPC) on Tuesday. 

Though part of Wall Street's exuberance today was due to impressive quarterly results from corporate America, all three of today's laggards got slammed immediately after their quarterly announcements. Boston Scientific Corporation plunged 6.3%, even after beating earnings estimates by more than 10%. If it ain't lowball earnings disappointing investors, it's usually revenue or guidance, and in this case Boston Scientific's revenue wasn't up to snuff. Consensus forecasts called for $1.8 billion in first quarter sales, but the medical device maker came in at $1.77 billion. Sometimes it's hard to wrap your head around Wall Street's obsession with sales growth over profitability, but earnings growth will eventually top out if the revenue growth isn't there to support it. 

PACCAR, which makes trucks and auto parks, as well as provides financial services, shed 3.5% today. Here's where you might really start scratching your heard about the market's reaction to earnings: PACCAR beat both sales and profit expectations last quarter, all while boosting its dividend by 10%. But as my colleague Rich Smith pointed out earlier today, appearances can be deceiving, and he makes a case that the quality of earnings at PACCAR isn't what it used to be.

Eaton makes electrical sensing and controls for aerospace customers, among other things. Source: Eaton website.

Finally, shares of power management company Eaton Corporation tumbled 3.2%, as investors looked past its earnings beat, focusing on Eaton's second-quarter financial forecast. If you took a shot in the dark, venturing to guess that forward-looking projections underwhelmed, you'd be right. Management put operating earnings per share between $1.05 and $1.15 for the current quarter, a far cry from the $1.29 Wall Street was looking for. Eaton said the low forecast was a result of its restructuring efforts, meant to increase long-term efficiencies in lines of business from aerospace to vehicle businesses, but investors didn't see the potential payoff.