I mentioned Jacobs Engineering (NYSE: JEC) recently as a stock that was underperforming on the long side. Shares are down more than 15% year to date making it the worst performer of my list of 10. But I still think the stock will be a big winner this year.

On the short side, American Express (NYSE: AXP) was a big gainer Tuesday, improving by nearly 10%. The reason for the move is an earnings report that almost met expectations. This time the proverbial penny miss got investors excited.

That is a mistake, though, and gives you an opportunity to sell this stinker before shares completely collapse. If you look at the numbers a little more closely, you'll find a deteriorating business.

Consumers are using cards less and making payments more infrequently. Defaults are increasing in a trend that is only gaining momentum. Given that many believe the lending fiasco will spread to credit card companies, American Express is to be avoided at all costs.

The end of what is becoming a deep freeze recession looks to be a 2010 event. AXP's CEO acknowledged that conditions were deteriorating. This week we can expect to learn that the economy shrunk by 5% or 6% in the fourth quarter.

It is not unreasonable to think that American Express' core business will likely shrink by another 50% before this is all said and done. Shares now trade for about $2 more than the lows reached just last week.

Given that business is still slowing, it is unlikely for this stock to post real gains any time soon. Tuesday's lift was more of a function of short covering than any real buying.

Who would buy this stock today knowing that the value of the business is likely to be lower down the road?

Louis Navellier's PortfolioGrader Pro, which offers free ratings for nearly 5,000 Wall Street stocks, rates AXP a D or Sell.

Jamie Dlugosch is a contributor to InvestorPlace.com.