There were some big winners on Wall Street today, with markets trading more than 1% higher for much of the day. Investors were excited to see fresh data showing a resurgent manufacturing sector in both the U.S. and Japan, though they seemed to get less enthusiastic as the day went on. The S&P 500 Index (^GSPC -0.88%) added 8 points, or 0.5%, to end at 1,614 on the first day of trading in the third quarter. But the benchmark index's three biggest losers all seemed to ignore the bullishness and stubbornly diminish their own market value.

To be fair, Coviden (COV.DL), which ended as the S&P's biggest laggard after slumping 8.6%, didn't do anything egregious to merit the brutal sell-off. As a matter of fact, the vast majority of the decline came after Friday's closing bell and before Monday's market open. The reason for the sudden dip had more to do with the fact that today was the stock's first full day of trading since spinning off its pharmaceutical division. 

FirstEnergy (FE 1.44%) also suffered a steep fall today, as shares dropped 2.8%. But FirstEnergy wasn't going through post-spinoff pains like Coviden; the electric utilities company was merely out of favor today. It's easy to understand why once you so much as glance at the company's financials: FirstEnergy's earnings have been on a steady downward trend in recent years, plummeting from $1.3 billion in 2008 to less than $800 million in 2012.

Lastly, another utilities company, Public Service Enterprise Group (PEG 0.98%), shed 2.5% Monday. It shouldn't be too surprising to see two utilities among the day's biggest underperformers, given that the sector as a whole was one of only two in the market to end in the red. At least, the company hasn't been following in FirstEnergy's fiscal footsteps. Public Service Enterprise Group has grown earnings from less than $1 billion in 2008 to $1.3 billion in 2012.