Have you ever owned a tweener?

A tweener, dear Fool, is like your pal Chuck. Still a great athlete, Chuck no longer rules the hardwood with his 40-inch vertical leap. He's become what we sports addicts call a gamer. He passes more. He's developed a nice shot from the corner. And, though he doesn't dunk as much, or as spectacularly, as he did, Chuck is still a force in the paint.

What we fans don't know is how long Chuck will be in the starting lineup. Chiseled veteran Abe has a wicked hook shot that won't quit. And Larry, the little guard whose hip-shaking moves smoke defenders, has the makings of a future superstar. Both are vying to cut into Chuck's minutes on the floor.

In Foolish parlance: Chuck is a tweener, Abe is a Rule Maker, and Larry is a Rule Breaker.

Growing up is hard to do
The stock market has plenty of Chucks. They'll either create billion-dollar fortunes as they come to dominate industries, as Cisco, Microsoft, and Google have, or they'll be destroyed in the process, as Gateway was.

Therein lies the problem. Investing in tweeners can be dangerous and exceptionally profitable -- the trick is picking your winners well, as David Gardner has. He produced nine years of 20% average returns hunting for misunderstood multibaggers in the making. His team at Motley Fool Rule Breakers continues the tradition today.

Let's have the list
You, too, can join in the effort, thanks to Motley Fool CAPS. Each week, we'll use the database to find three-star stocks that are expected to boost earnings by at least 15% annually over the next five years. Here is today's list:

Company

CAPS Rating (out of 5)

5-Year Growth Estimate

TASER International (NASDAQ:TASR)

***

35.0%

Eagle Rock Energy (NASDAQ:EROC)

***

30.7%

ExlService Holdings (NASDAQ:EXLS)

***

29.6%

Bois d'Arc Energy (NYSE:BDE)

***

25.0%

Semiconductor Manufacturing (NYSE:SMI)

***

17.5%

Sources: Motley Fool CAPS, Yahoo! Finance.

Bear in mind that this is not a list of recommendations. Instead, I offer these stocks as candidates for further research. But of these five, it's TASER I can't resist.

No surprise there. I'm a contributor to David Gardner's Motley Fool Rule Breakers growth investing service, and we've twice recommended TASER to subscribers. Like David, I believe the forward march of stun-gun technology is inevitable.

There are risks, however. Lawsuits remain and, even when they're victorious, TASER's top brass isn't always forthcoming about its legal record. I have serious doubts that truth-skimming is good for shareholders.

Now to be fair, I should say that my comments about CEO Rick Smith's interest in national legislation for TASER devices weren't accurate. Rick has never promised to work with Congress directly. What he told me in earlier interviews is that he'd be in favor of responsible regulation. TASER General Counsel Doug Klint recently confirmed by email that he still is.

Let's hope that's more than wishful thinking. TASER is winning orders as fast as camera-carrying gawkers post incidents to GooTube. Meaningful, but not oppressive, regulation could offer protection to both citizens and officers and pave the way for millions more in new TASER sales.

Do you agree? Disagree? Do your own due diligence and then check in with thousands of other investors at CAPS. And, if you'd like, add your own commentary. You'll be helping your fellow Fools and testing your ideas at the same time. Click here to get started now; the service is 100% free.

See you back here next week for five more growth stocks stuck in the middle.