No matter the market, there will always be losers -- a few lagging disappointments holding back a Wall Street rally or several big losers leading a bearish day. The S&P 500 (SNPINDEX:^GSPC) moved on up more than 0.6% on the day, 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 industrials to freight delivery, these stocks put a dent in Wall Street's Wednesday.

Retreat of the economic bellwethers
One of the biggest names on the stock market dropped into the red today, as Caterpillar (NYSE:CAT) took a hit. Shares weren't down by any horrific amount -- the top manufacturing stock lost 1.5% on the day -- but the losses were enough to rank Caterpillar among the worst notable laggards. The company reported that sales to dealers slumped by 13% over the past three months, including a withering 26% fall in sales to the Asia-Pacific region.

What's behind the bad news? Caterpillar's still struggling with high inventory, particularly in China, where the second-leading economy's sluggish growth lately has hurt industrial stocks everywhere. Chinese leaders set an economic growth target of 7.5% in 2013, but even though the country's not in bad shape, Caterpillar and its rivals are hurting. This stock's the worst performer on the Dow year to date, and investors have to be wondering how long it will be before it gets back on track.

It's not a good sign when one economic bellwether like Caterpillar's in the red, but rival Deere (NYSE:DE) also took a hit today. Shares of the manufacturer fell 3% after a Wells Fargo (NYSE: WFC) analyst downgraded the stock from "market perform" to "underperform." Why the downgrade? The analysis anticipated that falling corn prices in the near future would hurt demand for Deere's machinery; the company relies heavily on agricultural market's purchase of its products.

As with Caterpillar, however, sluggish global growth in the world's leading economies probably isn't helping Deere, either.

Rounding out three usually-solid stocks taking a hit today, shares of FedEx (NYSE:FDX) were walloped to the tune of 6.9% today, ranking it as the worst stock on the S&P 500 by far. Once again, we can pin much of the blame on Asia: FedEx announced that it will cut flight capacity to and from the region after it reported third-quarter earnings that plummeted 31% and missed analyst projections. FedEx is looking to slash costs as customers move toward cheaper means of transportation, and cutting its express business in Asia should help.

Will it be enough for FedEx to turn things around next quarter? Given that the company expects lackluster results from its international business to continue, perhaps not.