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'll enlist Motley Fool CAPS, our tool for rating stocks and analysts alike. With CAPS, we'll be tracking the long-term performance of Wall Street's best and brightest -- and its worst and sorriest, too.

And speaking of the best ...
With just hours to go before Visa (NYSE:V) makes its second-ever earnings report, stock speculator KeyBank Capital Markets has rolled the dice and placed its bet. Arguing that "Visa provides an excellent opportunity for investors looking for exposure to the global payment processing industry," and predicting top-line growth of "at least 12-15% and ... bottom line [of] more than 20% over the next three years," the Cleveland-based banker hopped off the fence and initiated coverage of the stock at "buy" this morning.

And yet, by definition, when a banker "initiates" coverage on a stock, it needs no track record on the stock. How then do we know whether its rating has any value? Examining the firm's record should give us a clue.

Let's go to the tape
Fortunately, CAPS can help with that. Having tracked KeyBank's performance since we started CAPS nearly two years ago, we know that KeyBank ranks in the very upper echelons of stock pickers. It is literally one of "Wall Street's Best," thanks to such savvy calls as:

Company

KeyBank Said:

CAPS Says

(5 max):

KeyBank's Pick Beating S&P by:

MasterCard (NYSE:MA)

Outperform

***

171 points

Medtronic (NYSE:MDT)

Outperform

****

22 points

Markel Corp (NYSE:MKL)

Outperform

*****

4 points

Of course, even a great stock picker has the occasional bad day. While KeyBank seems to have uncanny skill in predicting the trajectory of stocks beginning with the letter "M," it's made more than a few blunders elsewhere across the alphabet -- and more importantly, in the financial sector:

Company

KeyBank Said:

CAPS Says

(5 max):

KeyBank's Pick Lagging S&P by:

Cincinnati Financial 

(NASDAQ:CINF)

Outperform

***

24 points

Heartland Payment Systems  (NYSE:HPY)

Outperform

*****

5 points

Progressive

Outperform

***

3 points

Clearly, KeyBank has made some blunders, but its logic on Visa is sound. According to the banker, "there is a shift [under way] among individuals, companies and government agencies from using cash and checks to pay for goods to paying with credit, debit and prepaid cards." And while that may be so obvious as to go without saying, what you may not know is that "approximately half of payment transactions and volume were still paper-based" as of 2006. As one of the three biggest operators in the payment card industry (the others being KeyBank's successful MasterCard pick, and American Express (NYSE:AXP)), Visa seems ideally placed to profit as the other half of the world chooses plastic over paper.

Foolish takeaway
Personally, I'm leery of Visa's price -- 30 times next year's earnings seems a steep price to pay for even the 20% growth that KeyBank (and most other analysts) envision. But the logic is unassailable. If KeyBank should prove to have jumped the gun, and Visa disappoints tomorrow, make some time to examine the new valuation. At the right price, Visa's an obvious buy.