"Actions speak louder than words."

It's an old saying, with more than a grain of truth to it. So why do Wall Street firms get all the news coverage when they merely "initiate coverage" or "upgrade" their ratings on a company? Those are only words, after all; how the big boys act matters more. Luckily for Wall Street watchers, the Internet's made it relatively easy to track which professionals put their money where their corporate mouthpieces are. Just read MSN Money's list of which companies the Street is most actively buying.

But once we've done that, what next? "Monkey see, monkey do" isn't the soundest investment strategy. That's where Motley Fool CAPS can help. Our community intelligence system collects ratings from more than 27,000 lay and professional analysts. Then it overweights the most successful raters' opinions to come up with a "CAPS rating" from one star (the worst) to five (the best). If Wall Street's buying, and the smartest investors in Fooldom say it's right to do so, you should pay attention.

Wall Street vs. Main Street
Let's meet today's contenders:

Currently fetching

CAPS rating

Matrix Service (NASDAQ:MTRX)

$26.30

****

Synergetics (NASDAQ:SURG)

$4.84

***

Crystallex (AMEX:KRY)

$4.28

***

Cepheid (NASDAQ:CPHD)

$12.19

***

Vivus (NASDAQ:VVUS)

$5.79

**

Aventine Renewable (NYSE:AVR)

$20.61

*

Raser Tech (NYSE:RZ)

$8.21

*

Companies are selected from the "Institutional Ownership Up Last Month" list published on MSN Money on the Saturday following close of trading last week. Price increase and current pricing also provided by MSN Money on the same date. CAPS ratings from Motley Fool CAPS.

Main Street once again begged to differ with Wall Street's choices this week. On CAPS, we see three of the investment bankers' favorites receiving just average ratings from our raters, and three more actually getting the thumbs-down. In only one company do these boulevards of dreams intersect: oil service firm Matrix.

The bull case for Matrix Service
Over at Motley Fool CAPS, fully 63 out of 66 of our fellow investors give Matrix the thumbs-up, including all but one of the 30 top-ranked All-Stars who've gone on record about it. Here's what these super-investors have to say about Matrix:

  • mikolabruce likes the company's "rising fundamentals" and "upward estimates of earnings." (Speaking of which, b5l8 helpfully clarifies that "Matrix Service increased its 2007 revenue outlook to $510 million to $540 million, from its earlier view of $480 million to $520 million.") mikolabruce also cites Matrix's "great looking chart (if you are a chartist)."

  • And if you're not? Indian equity analyst NetscribeServcs gives a fuller explanation of the firm's business -- providing "general industrial construction and repair and maintenance services principally to the petroleum, petrochemical, power, bulk storage terminal, pipeline and industrial gas industries." NetscribeServcs argues that "the refining and petrochemicals turnaround business [that Matrix serves] is a high margin business, which provides Matrix an opportunity to improve pricing and increase market penetration."

So to recap -- mikolabruce and b518 say revenues are on the rise, while NetscribeServcs sees the potential for expanding those revenues' profit margins. Sounds like two halves of a pretty bullish thesis to me.

Time to chime in
But hey, we're not here to tell you what I think. This column is all about you, the individual investor. Motley Fool CAPS gives you a forum for expressing your opinions on the stocks you know best -- a chance to share your expertise with all the world. If you can add to the above discussion of Matrix (or any other company on today's list), then by all means, please click on over to CAPS and do so.

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 currently ranked 220th out of nearly 27,000 raters. The Fool has a disclosure policy.