The only thing better than buying into a great company is buying into a great company early in its growth cycle. Initial public offerings (IPOs) are the first sale of a company's shares to the public. They give investors like you and me a shot at an early arrival, but it's never quite as easy as that.

Many ground-floor opportunities head lower, into the basement. Some "can't-miss" and "layup" IPOs wind up as nothing more than airballs.

You can help your cause by learning to spot the differences between the winners and the losers. What makes a hot IPO great? What are the warning signs of a debutante stinker? Let's dive into the answers you need.

Anatomy of a hot new stock
The best way to unlock the secrets of tomorrow's big gainers is to dig into the market-thumpers of the past. Let's take a closer look at some of the best-performing IPOs over the past year:

IPO

Gain

Mindray Medical (NYSE:MR)

$13.50

126%

NYMEX (NYSE:NMX)

$59.00

98%

Data Domain (NASDAQ:DDUP)

$15.00

69%

Hansen Medical (NASDAQ:HNSN)

$12.00

106%

Lululemon (NASDAQ:LULU)

$18.00

81%

Don't rack your brain looking for a common theme. The winners come from all walks of life. Mindray and Hansen are helping stock up the health-care industry, but that has little to do with the yoga-class crowd donning the latest in Lululemon athletic apparel. NYMEX is a commodity trading juggernaut, but it's far removed from Data Domain's growing line of data storage appliances.

So what ties all of these hot issues together? It isn't necessarily pent-up market demand. Shares of Hansen Medical could have been had for as little as $10.02 -- 20% below its IPO price -- a month after it went public. Then it began its gradual climb into its current price in the $20s.

Sometimes a hot IPO shows its winning ways right away, of course. Virtualization software leader VMware (NYSE:VMW) went public at $29 on Tuesday. The stock popped at the open and kept trucking. Two days later, shares had nearly doubled to $57. It happens, but just know that slow starters can also become lucrative speedsters.

Brands such as NYMEX and Lululemon, along with investing themes such as health-care supplies and data storage, will provide an early advantage, but these success stories wind up earning the market's faith by producing strong quarterly results early in their tenure.

Fresh winners can do a portfolio good. Two of last year's hottest IPOs are recent recommendations in the Rule Breakers newsletter service. The growth-stock research service didn't get subscribers in on the offering price, but both stocks have beaten the market since being singled out.

So, what have we learned? Hot IPOs come from different sectors and are saddled with different investor expectations. Will that help you land the winners for 2007? It will if you accept the nuances behind the disparity. Most of the hotties came to market as quality players that went on to cement that perception in their heady quarterly growth performances.

The pitfalls of IPO investing
There are naturally plenty of dogs in any IPO litter. Orbitz (NYSE:OWW) went public last month at $15 a share. It has gone on to shed more nearly a third of its value. What went wrong? Isn't Orbitz a big brand in the hot online travel sector? Yes, Orbitz is a major player, but it's also increasing its bookings more slowly than its consistently profitable peers.

I like to weed out the potential portfolio-killers by looking for a few warning signs.

  • Is the IPO an exit strategy? If there are too many executive insiders selling, it may be.
  • Is this an inferior company trying to ride coattails? Many investors learned this the hard way in the dot-com bubble days, when pretenders like Pets.com and Webvan collapsed. Make sure that new stocks are as good -- if not better -- than their publicly traded peers.
  • Is the valuation realistic? Underwriters often reach too high for a company where the prospects are much lower. 
  • Is it a forced IPO? I hate it when a company rushes to go public as niche enthusiasm is waning. It's as if they've heard the last-call order from the bartender and rush to go public like they're scrambling to order one more beer. Whether it's a nervous private equity firm or a cash-strapped upstart, I avoid those "me too" copies like the plague.

So, where does that leave you? The IPO pipeline is never dry. There may be fewer new issues going public when the market is correcting, but quality ones find a way to earn their ticker symbols.

Don't let new stocks scare you. The Rule Breakers newsletter has recommended several new companies, in some cases just weeks after their market debuts. One of the picks just happened to be Mindray Medical. You're welcome to read up more on the reasons for its presence in the growth service's scorecard. A 30-day trial subscription will get you in for free.

Getting in early has its risks, of course. We've already explored how that ground-floor elevator sometimes stops down in the basement. However, getting in early is the best way to enjoy the longest ride up to the penthouse.

This article was originally published on March 10, 2007. It has been updated.

Longtime Fool contributor Rick Munarriz is a fan of new stocks and has even recommended several fresh IPOs to newsletter readers in the past. He does not own shares in any of the companies mentioned in this story. Rick is part of the Rule Breakers newsletter research team, seeking out tomorrow's ultimate growth stocks a day early. The Fool has a disclosure policy.