Based on the aggregated intelligence of 170,000-plus investors participating in Motley Fool CAPS, the Fool's free investing community, office-supply retailer Office Depot (NYSE: ODP) has received a distressing two-star ranking.

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

Office Depot facts

Headquarters (founded) Boca Raton, Fla. (1986)
Market Cap $1.19 billion
Industry Specialty stores
Trailing-12-Month Revenue $11.5 billion
Management Chairman/CEO Neil Austrian
CFO Michael Newman
Return on Capital (average, past 3 years) 0%
Cash/Debt $494.2 million / $748.4 million
Competitors Costco (Nasdaq: COST)
Staples (Nasdaq: SPLS)
Wal-Mart (NYSE: WMT)

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

On CAPS, 18% of the 617 members who have rated Office Depot believe the stock will underperform the S&P 500 going forward. These bears include All-Stars RedandBlack and BuffettJunior1, both of whom are ranked in the top 15% of our community.

Late last month, RedandBlack touched on Office Depot's seemingly unsustainable valuation: "Big box retailer with no online presence; the trend to paperless offices is still ongoing; trending to negative free cash flow. I don't understand how this company is valued for [its current market cap]."

In fact, Office Depot sports a three-year average net income margin of negative 5.5%. That's obviously lower than consistently profitable rivals like Costco (1.6%), Staples (3.3%), and Wal-Mart (3.6%).

CAPS All-Star BuffettJunior1 elaborates on the Office Depot bear case:

This stock will definitely underperform over the next 5 years. This is a dying company. ... Cash flow has been decreasing significantly over the past 10 years. Debt is slowly increasing. Overall everything is getting worse and worse. Eventually the company will be bought out, or it will have to declare bankruptcy.

What do you think about Office Depot, 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!

Motley Fool newsletter services have recommended shorting Office Depot; buying shares of Costco, Staples, and Wal-Mart; and creating a diagonal call position in Wal-Mart. The Motley Fool owns shares of Costco and Wal-Mart. Try any of our Foolish newsletter services free for 30 days.

Fool contributor Brian Pacampara owns no position in any of the companies mentioned. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Fool's disclosure policy always gets a perfect score.