Based on the aggregated intelligence of 165,000-plus investors participating in Motley Fool CAPS, the Fool's free investing community, United Airlines parent UAL (Nasdaq: UAUA) has received the dreaded one-star ranking.

With that in mind, let's take a closer look at UAL's business and see what CAPS investors are saying about the stock right now.

UAL facts

Headquarters (Founded)

Chicago (1934)

Market Cap

$3.5 billion

Industry

Airlines

Trailing-12-Month Revenue

$16.9 billion

Management

Chairman/CEO Glenn Tilton (since 2002)
CFO Kathryn Mikells (since 2008)

Return on Capital (Average, Past 3 Years)

(0.6%)

Compound Annual Revenue Growth (Over Past 3 Years)

(4.3%)

Cash/Debt

$3.5 billion / $9.3 billion

1-Year Return

348%

Competitors

AMR (NYSE: AMR)
Delta Air Lines (NYSE: DAL)
US Airways

Sources: Capital IQ (a division of Standard & Poor's) and Motley Fool CAPS.

On CAPS, 54% of the 768 members who have rated UAL believe the stock will underperform the S&P 500 going forward. These bears include raodyssey and All-Star MFBriguy, who is ranked in the top 0.5% of our community.

A few months ago, raodyssey showed skepticism over the stock's high-flying price: "The return of high yield business travelers is still very much in question and is essential to any turn around in this industry. ... So where are the facts supporting this run? "

In a more recent pitch, MFBriguy listed several more reasons not to hop aboard the stock:

- Increasingly intense competition
- Little pricing power and little/no competitive moat
- Highly regulated
- Unionized
- High fixed costs (airplanes, payroll)
- Non-differentiated product or service
- Exposure to volatile energy prices (fuel costs can and should be hedged, but apart from Southwest many airlines choose not to do so)
- Customer switching costs relatively low
- Highly sensitive to the global economy
- Management has poor track record for shareholder value creation

What do you think about UAL, or any other stock for that matter? If you want to retire rich, you need to protect your portfolio from any undue risk. Staying away from dangerous stocks is crucial to securing your financial future, and on Motley Fool CAPS, thousands of investors are working every day to flag them. CAPS is 100% free, so get started

Fool contributor Brian Pacampara owns no position in any of the companies mentioned. Southwest is a Motley Fool Stock Advisor selection. The Fool's disclosure policy always gets a perfect score.