For every stock out there screaming "buy me," others simply give us a nudge and a nod. While all the attention might be focused on their five-star peers, we can sift through Motley Fool CAPS to find four-star stocks giving us the "high sign" they're approaching greatness. 

These opportunities -- including familiar names and beaten-down companies -- rank higher than most of the other 5,400 starred companies, and it pays to investigate their potential. For consideration today, I have this handful of stocks on their way to fame.

  • Cornerstone Therapeutics (Nasdaq: CRTX)
  • Evolution Petroleum (NYSE: EPM)
  • Quantum (NYSE: QTM)

As the 170,000-plus CAPS members have chosen these companies as less obvious sources for tomorrow's great buys, let's see why they might merit your attention.

In the sight of greatness?
An earlier string of snafus for Cornerstone Therapeutics -- a need for cash had it selling a majority stake to an Italian pharmaceutical followed by a Food and Drug Administration warning it had distributed drugs without approval -- caused the drugmaker to rethink its direction. The company is now proving that its decision to rely more upon branded drugs and less on generic versions was the right one.

Cornerstone acquired Curosurf, an infant respiratory disease treatment, two years ago, and it's quickly become one of the company's top sellers with sales jumping 19% last quarter. Two asthma treatments, Zyflo CR and Zyflo, also saw sales double from the year-ago period.

Despite stiff competition from bigger, better-known rivals such as Abbott Labs (NYSE: ABT) and Merck, Cornerstone has done well for itself. Although profits narrowed in the quarter, they far exceeded analyst expectations.

CAPS member bobsweet isn't looking to its past, only to its future, and its current valuation which he deems to be very cheap.

If you really look indepth into this company then you would know it is poised to explode. Great forward P/E, P/S, P/Book while holding alot of cash with very little debt. 72.5% insider owned while still trading under 200M volume.

If the drugmaker leaves you breathless, let us know on the Cornerstone Therapeutics CAPS page or add it to your watchlist.

Dirt cheap?
Investors hear a lot about the various shale plays out there in the oil and gas field, the Marcellus, Bakken, Haynesville, Fayetteville, and more. The latest one that's gaining a lot of attention is the Niobrara, a spit of land in the Denver-Julesberg Basin, which goes from northeastern Colorado through southeastern Wyoming and into southwestern Nebraska. Samson Oil & Gas (NYSE: SSN) is expanding operations there, trying to make good on the promise of Devon Energy and Chesapeake Energy (NYSE: CHK), both of which also set up shop.

A play you don't hear too much about these days is the Austin Chalk, a longtime oil- and gas-producing tract near San Antonio. Lying just above the Eagle Ford Shale (another big name), this formation was first exploited as far back as the 1920s. Today, Evolution Petroleum is just one of a handful of companies working the space. Others include Swift Energy and Anadarko Petroleum, suggesting it won't be long before we're chalking this area up as another hot prospect.

Wall Street is unanimous in its opinion Evolution will evolve into a market beater, and the CAPS community is exceptionally bullish, too. mitleg finds the oil and gas player looking to be a sweet pick.

No debt, it has a great insider presence. It has been on a nice run. Their operations are in the US onshore. There is much to like here.

Add Evolution to the Fool's free portfolio tracker and keep an eye on all the news and analysis that develops out of the Austin Chalk.

It's not quantum physics
Back-up storage system maker Quantum has had a rough go of it since plunging after reporting it failed to close a number of deals with enterprise-level customers by the end of the third quarter. That led to a 3% drop in revenues with earnings missing analyst estimates.

While failing to close deals in time for end-of-quarter reporting is a common enough occurrence, you expect the following quarter to make up for it as the sales just get closed later on. But Quantum's guidance was well below what the Street thought revenues would come in at (even before the deals getting done), which led to the stock dropping 25% in one day.

Shares have continued to trade down since then, but industry leader EMC (NYSE: EMC) got an analyst upgrade, and that helped bolster the entire sector, Quantum included. The analyst is looking for the industry to get hot again.

Although initially caught by the blown quarter, highly rated CAPS All-Star member EnigmaDude suggested back in January that 2011 was the time we'd see storage grab headlines once more. If Quantum's too volatile for your portfolio, you can monitor its progress by adding it to your watchlist.

A great opportunity for you
Investor sentiment suggests these four-star investments still seem to be on their way to five-star greatness, but it pays to start your own research on these stocks on Motley Fool CAPS. Read a company's financial reports, scrutinize key data and charts, and examine the comments your fellow investors have made all from a stock's CAPS page.

Sign up today for the completely free service and let us hear what you have to say about the great and almost great companies that interest you.

The Fool owns shares of Abbott Laboratories, Devon Energy, EMC, and Evolution Petroleum. Motley Fool Alpha LLC owns shares of Abbott Laboratories and Chesapeake Energy. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. 

Fool contributor Rich Duprey does not have a financial position in any of the stocks mentioned in this article. You can see his portfolio here. The Motley Fool has a disclosure policy.