Bad days. We all have them; some of us deserve them.

Here are five stocks whose naughty ways drew investors' scorn on Monday:

Company

Closing Price

CAPS Rating
(out of 5)

%
Change

52-Week
Range

Angiotech Pharmaceuticals (Nasdaq: ANPI)

$2.54

***

(15.89%)

$1.50-$7.90

Openwave (Nasdaq: OPWV)

$2.06

**

(15.23%)

$1.20-$10.58

American Dairy (NYSE: ADY)

$12.52

****

(9.99%)

$6.77-$26.00

Mattel (NYSE: MAT)

$20.00

***

(8.17%)

$16.42-$29.46

Qimonda (NYSE: QI)

$3.63

**

(6.20%)

$3.51-$17.29

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

Naughty?
Well, OK, we can't exactly call these stocks naughty. There are days when five-star winners and newsletter recommendations appear here. Today, though, isn't one of those days.

As 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 97,000-person-strong Motley Fool CAPS community of stock pickers speaks with a poor rating or a negative pitch. You should too.

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

Worse
We begin with Mattel. It disintegrated any good tidings it may have created with good fourth-quarter results when it reported on Monday a massive $46.6 million, or $0.13 per share, first-quarter loss. Wall Street had expected a $0.01-per-share profit.

Rising costs, including labor and legal expenses, were to blame, management says. Here's how CEO Robert Eckert put it as reported by the Associated Press: "Labor costs are increasing dramatically in China."

Tough break. But there may be ... Waitaminute.

Did he just say the cost of Chinese labor is increasing dramatically? Wonderful! Does that mean I can have my mortgage back? Color me skeptical.

Worser
Next up is American Dairy, which appeared in this column in December for various tussles with its bookkeepers and the SEC. We have more of the same today.

On Friday, the Chinese milk maker sued its former auditors over indiscretions that, it says, led directly to an SEC investigation. Management is seeking $10 million in damages.

Goodbye, profits. Hello, legal fees.

Worst
But our winner is Qimonda, another former guest in this column, which is 77% owned by fellow chip maker Infineon (NYSE: IFX).

On Monday, the company said its second-quarter year-over-year revenue declined by 58%. Net loss narrowed from the first quarter thanks to cost improvements, but, apparently, more are needed. Management plans to cut 10% of its workforce and, combined with other trimming, realize 180 million euros in annualized savings.

That, however, still isn't enough for Infineon. Executives there confirmed a writedown of 1 billion euros in the value of its Qimonda stock to help expedite the search for a buyer.

And if one isn't found? Reuters reports that Infineon is willing to give away shares to its own shareholders if that's the only way to dump its stake.

Translation: Qimonda's shares may prove to be -- do I have this right? -- tchotchkes? Yikes.

Qimonda and its maybe-they'll-make-good-party-favors shares ... Monday'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.

Fool contributor and Rule Breakers writer Tim Beyers, who is ranked 16,485 out of more than 97,000 participants in CAPS, hopes that Keith Olbermann doesn't mind the blatant theft of his "Worst Person in the World" segment from Countdown. Remember, Keith, imitation is the sincerest form of flattery.

Tim didn't own shares in any companies mentioned in this article at the time of publication. The Motley Fool's disclosure policy thinks that lima beans are the worst veggies in the world.