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

(5 Max)

%

Change

52-Week

Range

Dollar Thrifty (NYSE: DTG)

$16.40

*

(36.97%)

$16.27-$55.30

99 Cents Only Stores (NYSE: NDN)

$7.79

**

(10.15%)

$6.05-$16.21

American Express (NYSE: AXP)

$47.66

***

(3.91%)

$41.15-$65.89

Penwest Pharmaceuticals (Nasdaq: PPCO)

$4.35

*

(17.92%)

$3.22-$15.42

Lifetime Brands (Nasdaq: LCUT)

$10.92

****

(9.98%)

$9.17-$23.43

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.

But 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 83,000-person-strong Motley Fool CAPS community of stock pickers speaks with a poor rating or a negative pitch.

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

Worse
We begin with American Express, which was on the business end of a UBS downgrade. The All-Star analysts there now rate the stock "sell," citing concerns over a recession that would crimp consumer spending.

I've no idea how hard AmEx would get hit if a recession were to occur. But as a credit card company, American Express has much more to lose than fast-growing network operators such as MasterCard (NYSE: MA) or Visa.

Visa, in particular. Just as AmEx is being taken behind the woodshed by Wall Street's white-shoe wannabes, Visa is prepping a $10 billion IPO for later this year. And why not? Visa says that net income was up 107% in the December quarter.

Worser
Next up is 99 Cents Only Stores, to which top fund manager Chuck Akre delivered strong words in a letter filed with the Securities and Exchange Commission. Quoting:

We continue to see significant potential for operational and capital improvement at this business. So far you have been unsuccessful capitalizing on this potential or even articulating a plan for doing so in the future.

Ouch.

But of course, Akre is right. Gross margin has declined sequentially in each of the past three quarters, and return on capital has either been minimal or negative in six of the past seven quarters.

Worst
But our winner is car rental company Dollar Thrifty, which cut its full-year earnings outlook from $1.75 to $1.85 per share to $0.90 to $0.95. CEO Gary Paxton explained in a statement:

In the fourth quarter we experienced progressively weaker industry demand in the travel market, excess fleet capacity in the industry, and a weakening used car market. The demand over the Thanksgiving and Christmas holidays was much weaker than we had originally expected. Lower than expected revenue drivers including a decline in consumer demand and lower revenue per day impacted fourth quarter results by $0.40 to $0.45 per diluted share versus previous guidance. [Emphasis added.]

Talk about a broken crystal ball. Dollar Thrifty and its in-need-of-a-tow business model ... 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.