Editor's note: An earlier version of this article indicated that some chickens had avian flu. According to Tyson, the birds had been exposed to a strain different from H5N1, and none appeared to have contracted avian flu. The Fool regrets any confusion.

Bad days. We all have them. Some of us deserve them. Here are five stocks whose naughty ways drew investors' scorn on Tuesday:

Company

Closing Price

CAPS Rating (5 max)

Change

52-Week Range

Layne Christensen (NASDAQ:LAYN)

$46.12

*****

(13.26%)

$32.08-$59.19

Tyson Foods (NYSE:TSN)

$16.98

**

(7.97%)

$12.81-$24.32

Downey Financial (NYSE:DSL)

$5.89

*

(6.80%)

$5.69-$73.61

Wachovia (NYSE:WB)

$21.92

**

(6.32%)

$22.72-$54.54

Orbitz Worldwide (NYSE:OWW)

$7.15

**

(4.79%)

$4.51-$15.00

Sources: The Wall Street Journal, Yahoo! Finance, Motley Fool CAPS.

Naughty?
Well, OK, we can't exactly call the stocks on this list naughty. There are days when five-star winners and newsletter recommendations appear here. Today, sadly, is one of those days.

If you're an investor, you'll have plenty of bad days. The trick is to avoid dating -- or, worse, marrying -- your losers. That's why I listen when our 105,000-person-strong Motley Fool CAPS community of stock pickers speaks with a poor rating or a negative pitch. You should, too.

Therefore, here is today's list of the worst stocks in the world.

Worse
We begin with Orbitz Worldwide, which inked a new rewards card deal with Visa (NYSE:V) and Capital One (NYSE:COF).

I don't oppose the move. To the contrary; I applaud it. Business travelers tend to shop for deals using rewards cards, to more easily pile up the points for luxury vacations. (Believe me, I know a little something about this strategy.)

But the new card should change nothing in your analysis of this underperforming business. Why? Orbitz has had a Visa card for years. Switching from previous banker Barclays to Capital One isn't likely to help management do a better job of deploying capital on shareholders' behalf.

Worser
Next up is Tyson Foods, which on Tuesday admitted that it would have to destroy 15,000 chickens found to have been exposed to H7N3, an avian flu strain related to the one which which evoked widespread fear in 2006.

But there could be more than an inventory hit at work here. Tyson and peers such as Pilgrim's Pride are big exporters. Tyson gets 6% of its revenue from overseas markets such as Russia. A ban on importing chicken from the U.S. -- a possibility, due to bird flu fears -- could put that 6% at risk.

Worst
But our winner is Downey Financial, a former guest in this column because of its risky loans, which on Tuesday was served notice by Standard & Poor's. The ratings company has put the lender on CreditWatch, with negative implications:

This action was taken in response to our increasing concerns about the substantial negative effect the deterioration in California's housing market is having on Downey's credit performance, financial profile, and profitability.

Translation: We're not sure Downey has the liquidity to repay its obligations.

My sense is that S&P has it right. California's housing market is so bad that a San Diego developer recently resorted to a buy-one-get-one-free promotion on homes. (Really.)

Downey, meanwhile, has seen net interest income decline 26% and noninterest income plummet 56% over the trailing 12 months. More than 12% of its loans were classified as "nonperforming" through March.

Downey Financial and its credit-crunched loan portfolio ... Tuesday's Worst Stock in the CAPS World.

Do you agree? Disagree? Let us know what you think by signing up for CAPS today. It's 100% free to participate.

I'll be back tomorrow with more stock horror stories.