Based on the aggregated intelligence of 170,000-plus investors participating in Motley Fool CAPS, the Fool's free investing community, online professional network operator LinkedIn (NYSE: LNKD) has received the dreaded one-star ranking.

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

LinkedIn facts

Headquarters (Founded) Mountain View, Calif. (2002)
Market Cap $8.34 billion
Industry Internet information providers
Trailing-12-Month Revenue $292.3 million

Co-Founder/Chairman Reid Hoffman

CEO Jeffrey Weiner

Trailing-12-Month Net Income Margin 5.4%
Cash/Debt $106.06 million / $0

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

On CAPS, 90% of the 678 members who have rated LinkedIn believe the stock will underperform the S&P 500 going forward. These bears include Fool Rich Smith (TMFDitty) and kurtdabear, both of whom are ranked in the top 15% of our community.

Late last week, Rich succinctly summed up the LinkedIn bear case: "A barely profitable, overpriced tech stock that even Rick Munarriz can't stamp 'approved?' I shudder at the thought."

In fact, LinkedIn currently sports an outrageous EV/EBITDA ratio of almost 100. That obviously represents a massive premium to fellow professional community operator Dice Holdings (NYSE: DHX) (17.4), as well as employment solutions specialists Monster Worldwide (NYSE: MWW) (19.5) and 51job (Nasdaq: JOBS) (25.0).

CAPS All-Star kurtdabear expands on the LinkedIn underperform argument:

Betting against IPO's is nearly a sure thing: Recent averages have shown that 90% are worth less on their first anniversary than they were on the day they went public. When you get a big-name tech company with practically no earnings, odds are pretty good that things will be going south soon -- especially when the CEO is warning that LNKD will lose money this year. Google this ain't.

What do you think about LinkedIn, 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!