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'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 ...
CIBC World Markets upgraded the stock of Yahoo! (NASDAQ:YHOO) this morning, on the basis of a better-than-expected performance in its third-quarter earnings report and a 26% decline from its post-earnings high of $33.63 per share arguing in the stock's favor. On the downside, the analyst sees risk in slower online-ad spending and possible market-share attrition at the hands of rivals such as Google (NASDAQ:GOOG) and Microsoft (NASDAQ:MSFT). That said, though, CIBC believes the downside risk is so limited at this point that Yahoo! now deserves a "sector outperform" rating.

Let's go to the tape
At this point in this column, I would ordinarily turn to CAPS for a glance at CIBC's CAPS rating to help us determine whether the analyst has a good track record overall, and whether perhaps it's a little better or a little worse than its own average when covering Internet stocks.

No such luck.

I've often wanted to write about CIBC, because it's one of the more active stock raters tracked by CAPS' data provider, Briefing.com. Problem is, as I've discovered from talking this over with our CAPS techies, CIBC is "invisible" to CAPS. We get the data on the upgrades and downgrades, all right, but because CIBC sticks to qualifying its outperform/underperform ratings with the prefix "sector," we cannot in good conscience count these ratings as CIBC's opining that a stock will or will not outperform the market at large.

It wouldn't be fair to the analyst to dock it 20 points for wrongly predicting on Oct. 8 that Novatel (NASDAQ:NVTL) would outperform the S&P 500, or 1 point for saying on Sept. 27 that Magna (NYSE:MGA) would -- because that's not what CIBC said. It said only that these stocks would outperform their software and auto-parts-maker sectors, respectively.

Similarly, it's not fair to other CAPS players to give CIBC half a point's worth of credit for correctly predicting on Oct. 19 that J. Crew (NYSE:JCG) would outperform the S&P 500, or 27 points for calling Audiocodes (NASDAQ:AUDC) correctly on Sept. 12.

Foolish takeaway
CIBC's chosen method of rating stocks is somewhat less than helpful to you, the investor. It's a crying shame that the analyst lacks the intestinal fortitude to tell us whether a given company is an objectively good investment and instead limits itself to weighing relative valuations within a peer group.

But on today's Yahoo! call in particular? I think CIBC's invisibility is helping it to dodge a bullet on this upgrade. If we were to hold CIBC accountable for endorsing a stock that has a price-to-earnings ratio of 50 and is predicted to grow its profits half as quickly, at 25% per year, I suspect that CIBC's CAPS rating would suffer mightily for the oversight.

Yahoo! is a Motley Fool Stock Advisor recommendation, and Microsoft is a selection of Inside Value.

Fool contributor 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's ranked No. 793 out of more than 74,000 players. The Fool has a disclosure policy.