Cheap stocks can get cheaper. They often do.

The problem is that "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 are instead value traps -- stocks that deserve the multiples for which they trade, and punish the dumpster divers who buy them.

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


Company

CAPS Rating
(5 stars max.)

2004 Book Value

Return
Since

Saks (NYSE:SKS)

*

1.01

(67.9%)

Tyson Foods (NYSE:TSN)

**

1.20

(34.5%)

Celera (NYSE:CRA)

***

1.10

(32.2%)

Stillwater Mining (NYSE:SWC)

***

1.12

(57.7%)

IAC/InterActive (NASDAQ:IACI)

***

1.56

(79.4%)

Sources: Motley Fool CAPS, Capital IQ.

Watch out!
How can you avoid value traps like these? My favorite method is borrowed from professor Aswath Damordaran, author of Investment Fables. In it, he 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 for when you're in the weeds
Our 125,000-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. As a qualifier, the candidates also had to trade no more than 25% above their 52-week low, leaving plenty of room for further gains.

Of the 176 stocks that CAPS found hiding in the weeds, Allied Irish Banks (NYSE:AIB) intrigues me most this week. The details:

Metric

Allied Irish Banks

Recent price

$5.63

CAPS stars (5 max)

*****

Total ratings

2,018

Percent bulls

97.2%

Percent bears

2.8%

Price-to-book

0.18

ROE

20.6%

% Above 52-week low

23.7%

Sources: CAPS, Yahoo! Finance, Capital IQ. Data current as of Jan. 6, 2009.

Impressive numbers, eh? I'll say. Here's one more: Owners of Allied Irish Banks yield -- wait for it -- 35% from dividends at current prices. A 35% return with no capital appreciation required. That's astounding.

But it may also prove too good to be true. If the current financial crisis has taught us anything, it's that banks such as Citigroup (NYSE:C) can lose equity just as fast as they earn it -- especially if the value of the equity-producing assets, the ones responsible for Allied Irish's super-low price-to-book ratio, are overstated.

And yet, there's still a lot to like about Allied's position, writes CAPS All-Star BigDMan64. Quoting from his recent pitch:

I hate banks and financial services. I shorted many of the regional banks about a year ago with much success. I am not in favor of the bailouts which appear to be used both in the US and Europe to purchase additional deposits rather than increase liquidity. That having been said, this pick is a no brainer. Ireland may be the soundest economy in Europe. Other than Lloyds and National Bank of Greece, this company has the best management with a conservative track record and holds little, if any bad paper.

Allied Irish might not have much bad paper, but that didn't stop the Irish government from stepping in. It forced Allied Irish to take 2 billion euros of capital, in return for preferred stock paying 8% interest. That will have to be paid before any dividends can reach common shareholders. Thus, the question remains: Will Allied Irish be able (and willing) to pay its dividend in 2009?

What do you think? Is Allied Irish Banks the bargain it appears to be, or a value trap waiting to snap? Let us know by signing up for CAPS today. It's 100% free to participate.

See you back here next week with more bargain-basement Foolishness.

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Allied Irish Banks is a Motley Fool Global Gains recommendation. The Fool owns shares of Allied Irish Banks.

Fool contributor Tim Beyers also contributes to the market-beating Rule Breakers service. Tim didn't own shares in any of the stocks mentioned in this article at the time of publication. Check out his portfolio holdings and Foolish writings, or connect with him on Twitter as @milehighfool. The Motley Fool is also on Twitter as @TheMotleyFool. Its disclosure policy is a bargain at any price.