At The Motley Fool, we poke plenty of fun at Wall Street analysts and their endless cycle of upgrades, downgrades, and "initiating coverage at neutral." So you might think we'd be the last people to give virtual ink to such "news." And we would be -- if that were all we were doing.

But in "This Just In," we don't simply tell you what the analysts said. We'll also show you whether they know what they're talking about. To help, we've enlisted Motley Fool CAPS, our tool for rating stocks and analysts alike. With CAPS, we track the long-term performance of Wall Street's best and brightest -- and its worst and sorriest, too.

Here we go again
It has been nearly three weeks since JPMorgan Chase stamped a big ol' buy rating on American Express (NYSE: AXP). So far, the pick isn't exactly working out as planned -- the stock's down nearly 4% against a 3% rise in the S&P 500. According to JPMorgan, AmEx's bias toward issuing pay-if-off-monthly credit cards plays right into the trend of a "deleveraging" consumer. Also according to JPMorgan, this makes American Express a better bet than credit card purveyors Capital One (NYSE: COF) and Discover Financial (NYSE: DFS).

When I heard about JPMorgan's upgrade earlier this month, I told you to ignore it -- and I told you why. Today, we learn that Foolish minds think alike, as one of the very best investors on Motley Fool CAPS pipes up and tells you to stop buying American Express ... for basically the same reasons I offered back on Dec. 2.

Bright and early Monday morning, Stifel Nicolaus announced it's pulling its buy rating on American Express on the following theory: A law currently before Congress aims to cut the interchange fees that merchants pay debit-card issuers by as much as 75%, to as little as $0.07 per transaction. Says Stifel, it's MasterCard (NYSE: MA) and Visa (NYSE: V) that will bear the brunt of this change -- simply because they're the biggest plastic hawkers out there. But Stifel doesn't let American Express off the hook, either.

According to the analyst, steep cuts in the cost of using MasterCard and Visa debit cards are going to "significantly increase pressure on higher-cost payments alternatives like Amex" credit cards. Worse, Stifel sees the assault on high debit interchange fees as only the beginning of Congress' crusade. Next up: Interchange fees on credit cards -- American Express' bread and butter.

So what?
Why should you care what Stifel Nicolaus thinks about the prospects at American Express? It's a fair question. After all, Stifel's record in the bank-o-sphere really isn't much to brag about. Of its bets on commercial banks, 62% have gone awry; half its recommendations in thrifts and mortgage finance missed the mark, leading to simply staggering losses on stocks like People's United Financial (Nasdaq: PBCT) and Wells Fargo (NYSE: WFC):

Companies

Stifel Says

CAPS Rating
(out of 5)

Stifel's Picks Lagging 
S&P by

People's United Outperform *** 37 points
Wells Fargo Outperform *** 34 points

And yet, the farther you get from the concept of banking, and the closer to credit, the picture changes -- dramatically. Focus on the credit card industry in particular, in fact, and it turns out Stifel really does have a good grasp of the economics of this business -- and knows where to find the winners:

Companies

Stifel Says

CAPS Rating 
(out of 5)

Stifel's Picks Beating 
(Lagging) S&P by

American Express Outperform *** (2 points) (picked twice)
MasterCard Outperform *** 13 points
Visa Outperform *** 17 points (picked twice)
Discover Outperform ** 22 points
Capital One Outperform * 50 points (picked three times)

So, will Stifel astound us again with its stock-picking wizardry? For all the reasons I laid out for you earlier this month, I believe it will. Like I said three weeks ago, "I'm not optimistic" about American Express' chances for outperforming the market. Sure, 13.7 times earnings doesn't look like a lot to pay for a stock -- but when that stock's only expected to grow 11% per year over the long term (as American Express is), it's hardly a bargain, either.

Meanwhile, a share of MasterCard will cost you less than 16 times earnings, and Visa's only fetching a 16.3 P/E today. With growth rates approaching (or surpassing) 20% in each case, I think there's a whole lot more value to be found in these shares.

Last but not least ...
In today's recession-weary world, I simply don't believe that merchants will continue to put up with the above-market interchange American Express charges for its services -- fungible services, which MasterCard and Visa provide just as well, and for less money. And as its merchant clients defect, American Express' profits will melt away.

Don't expect the company's cheaper P/E today to save you when that happens tomorrow.

American Express and Discover Financial Services are Motley Fool Inside Value picks, and Rich Smith does not own shares of any company named above. You can find him on CAPS, publicly pontificating under the handle TMFDitty, where he was recently ranked No. 631 out of more than 170,000 members. The Motley Fool has a disclosure policy.

Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors.