Stocks climbing to 10 times their original price are rare breeds -- but they're not impossible to find. Especially when you have Fools for friends.

The market's best stocks include companies that have risen dozens of times in value by taking advantage of the market's weaknesses. These aren't penny stocks; they're viable companies with sound business prospects that are achieving phenomenal returns. Finding just one or two of these monstrously successful firms can help you establish a winning portfolio.

Stalking the monster
To find tomorrow's winners, we've enlisted the help of more than 170,000 monster trackers at Motley Fool CAPS. We've compiled a list of the most successful CAPS members, dubbed All-Stars, whose picks have doubled, tripled, or even quadrupled in price. Then we've plucked out some of their recent picks for stocks they find equally promising.

Player

CAPS Member Rating

Monster Stock

CAPS Score

Recent Stock Pick

CAPS Rating (out of 5)

vanamonde 99.99 Macerich 818.31 Delcath Systems (Nasdaq: DCTH) **
JakilaTheHun 99.95 Genworth Financial 475.42 Delta Air Lines (NYSE: DAL) *
BravoBevo 100.00 General Growth Properties 1179.52 Zix (Nasdaq: ZIXI) ***

Score is how many percentage points that pick is beating the S&P 500.

Of course, this is not a list of stocks to buy -- or, for those monster stocks that our CAPS All-Stars have already found, sell. Just consider them starting points for your own further research of extreme buying opportunities.

In search of bigfoot
Market reaction to "refuse to file" letters is creating buying opportunities for investors willing to wade into a turbulent stream, and considering the volume of RTFs coming out of the Food and Drug Administration these days, it seems there's plenty of options to pick from.

Delcath Systems got one a week ago, sending its stock into a tailspin. Gilead Sciences (Nasdaq: GILD) got one the month before, and Santarus (Nasdaq: SNTS) got one Monday. But, as the Fool's Brian Orelli points out, these letters are better than an outright rejection because they give the biotechs a chance to rectify any holes in their application. While there could be problems down the road unrelated to the application itself -- there might be problems with the actual science -- if you're backing these drugmakers, then the big drop in price they experience becomes a buying opportunity.

CAPS member ryansal thinks there are enough catalysts ahead of Delcath that the tumble it took because of the "refuse to file" letter provides investors with an opening.

[Delcath] has a lot of cash for a development stage company. And unlike the run up in december to almost $12 [before] the [new drug application] , this year they have exposure in Europe ... could we then see a run up to $15-$16 before the next [new drug application] in Sept 2011?? Something to think about ...

Head over to the Delcath Systems CAPS page and seek relief from the stock price drop it suffered over the past week.

One big nuclear family
A bet on Delta Air Lines becoming the next monster stock is a true contrarian play if there ever was one. Mideast unrest, rising fuel prices, a precarious profit picture -- all these factors would suggest that Delta, American Airlines parent AMR (NYSE: AMR), and even Southwest Airlines (NYSE: LUV) might be in for a bit of turbulence in the short run.

A lot of airlines have image problems, and Delta's no different, but its record fine for discriminating against passengers with handicaps and destroying emails relevant to an air passenger lawsuit over baggage fees certainly does nothing to endear itself to the flying public. Those issues have CAPS member bargain123 expecting the airline to fall further, echoing 44% of other CAPS members rating Delta, who anticipate it will underperform the broad market averages.

Fly alongside Delta and follow its progress by adding the stock to the Fool's free portfolio tracker.

Can you hear me now?
By relying upon a network of third-party partners, email encryption specialist Zix was able to more than just get by in the latest quarter. Revenue surged 25% while profit remained flat from the year-ago period. But those resellers now account for more than half of Zix's new business and underscore the confidence the CAPS community placed in it earlier this year by bumping up its rating.

Although the market isn't particularly enamored of the results right now, CAPS members remain decidedly bullish. Indeed, of the more than 100 All-Stars who have weighed in on the cryptologist, only one suggests it won't ultimately outperform the market.

With shares almost 30% below their 52-week high and its great growth prospects, it appears much of the downside risk has been priced into the stock. But you can add Zix to your watchlist, then head over to the Zix CAPS page and tell us if you think it's cracked the code on future growth.

A chance for scary growth
It takes more than a few All-Star picks and a quick pitch to make buy or sell decisions, so start your own research on these stocks on Motley Fool CAPS and find other opportunities with monster potential.