Cheap stocks can get cheaper. They often do.

Unfortunately, "cheap" is a relative term. Precious few stocks that trade for low price-to-earnings ratios or below book value are real bargains. They look enticing, but instead, they're value traps -- stocks that deserve the multiples for which they trade, and punish the garbage-grabbers who buy them.

But don't take my word for it. Here are five "cheap" stocks that trapped bargain-hunting prey:

Company

CAPS Stars (out of 5)

2004 Price-to-Book Ratio

Return Since

Tenet Healthcare (NYSE:THC)

***

1.32

(50.3%)

Micron Technology (NYSE:MU)

***

1.42

(39.2%)

Advanced Micro Devices (NYSE:AMD)

**

1.89

(59.9%)

Tyson Foods (NYSE:TSN)

**

1.37

(25.1%)

KB Home (NYSE:KBH)

*

1.80

(63.5%)

Sources: Motley Fool CAPS, Capital IQ, Yahoo! Finance.

Watch out!
How can you avoid value traps like these? My favorite method is borrowed from professor Aswath Damodaran. In his book Investment Fables, Damodaran counsels investors to measure low price-to-book stocks by their returns on equity (ROE).

Makes sense to me. "Book value" is shorthand for equity. A low price-to-book stock is priced as if management won't produce high returns from the equity capital afforded it. Find a stock that defies this maxim -- a stock with an above-average and rising ROE -- and you may have found a bargain.

A machete when you're in the weeds
Our 140,000-member-strong Motley Fool CAPS database is a great place to start your search. I ran a screen for well-respected stocks trading for less than twice book value, and whose returns on equity were 10% or more. Qualifiers were also trading no more than 25% above their 52-week low, leaving plenty of room for further gains.

Of the 16 stocks that CAPS found hiding in the weeds, The Ensign Group (NASDAQ:ENSG) intrigues me this week. The details:

Metric

The Ensign Group

Recent price

$14.00

CAPS stars (out of 5)

*****

Total ratings

137

Percent bulls

97.1%

Percent bears

2.9%

Price-to-book

1.68

ROE

17.9%

% Above 52-week low

24%

Sources: CAPS, Yahoo! Finance.
Data current as of Oct. 1.

Not long ago, Fools saw this operator of long-term care facilities as a stock poised to pop. And that still seems to be true. All 64 the top CAPS investors rating Ensign -- Fools whose picks have performed better than 80% of the broader community -- say this stock will outperform, a good sign.

What do these experts see? "Long term play on long term care," wrote former Top Fool tenmiles in May. "Recent weakness in stock likely provides a good fundamental and technical entry point for this small cap, health consolidator with attractive growth. Buyer at $13.20."

He's up about 7% since, a market-lagging performance. The good news? At 9.5 times earnings, the stock trades for less than its industry average multiple, and for far less than larger peers, such Kindred Healthcare (NYSE:KND). I'd be a buyer at these levels.

But that's also just my take. Would you buy shares of The Ensign Group at today's prices? Let us know by signing up for CAPS today. It's 100% free to participate.

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