No matter the market, there will always be losers, whether it's a few lagging disappointments holding back a Wall Street rally, or several big losers leading a bearish day. The S&P 500 (SNPINDEX:^GSPC) ended the day by gaining a fraction of a percent, but several notable big names helped to weigh down the index and make investors pull their hair out in frustration. Here are the three worst stocks today that you need to know about. From materials to the Internet, these stocks put a dent in Wall Street's Wednesday.

Falling prices send today's losers down
Where do I begin with Cliffs Natural Resources (NYSE:CLF)? Today's No. 10 laggard on the S&P 500 lost another 4.9% and has made this list with uncomfortable frequency in 2013. Cliffs is now  down more than 41% for the year, and the plummeting price of iron ore -- spot iron prices are down 13% from the late February peak -- aren't helping this stock dig out of its hole.

Cliffs reported earlier this week that it will idle a pellet plant in Quebec, with pricing and higher costs forcing the company's decision. As the economy sluggishly churns along and China draws back on infrastructure spending, don't expect these worrying trends to subside any time soon.

The same conditions are slamming U.S. Steel (NYSE:X), another one of today's top laggards after shares fell 3.1%. The Chinese infrastructure slump's doing no favors to this age-old company, whose stock has fallen 20% year to date. Like with Cliffs, U.S. Steel is in for a tough time until prices rebound -- and with the economy still stuck in neutral, investors will probably be left waiting for some time before that happens.

Imports are also threatening U.S. Steel's future. Chinese steel  imports to the U.S. rose 34% in 2012 and are expected to rise further this year, putting more downward pressure on prices and far outstripping the growth in actual usage of steel. If that keeps up, U.S. Steel won't even be able to capitalize on growth when prices and demand do rise again.

Finally, eBay (NASDAQ:EBAY) rounds out the top three losers today, as shares fell 3.7%. The company's online payment subsidiary, PayPal, purchased mobile-app company Duff Research today in an attempt to stave off mobile and online payment competitors. Investors didn't take too kindly to the purchase, but eBay's move to firm up its grasp on mobile payments is a good one, particularly with the likes of Square and other rivals encroaching on its territory.

Fool contributor Dan Carroll has no position in any stocks mentioned. The Motley Fool recommends and owns shares of eBay. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.