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

comScore (NASDAQ:SCOR)

$21.45

***

(22.54%)

$17.31-$42.00

Virgin Mobile (NYSE:VM)

$2.91

**

(15.65%)

$1.90-$15.69

Grubb & Ellis (NYSE:GBE)

$4.49

**

(10.02%)

$3.80-$12.15

RH Donnelley (NYSE:RHD)

$3.23

*

(9.52%)

$3.19-$78.10

Hoku Scientific (NASDAQ:HOKU)

$5.52

*

(8.76%)

$5.50-$14.88

Sources: The Wall Street Journal, Yahoo! Finance, Motley Fool CAPSĀ as of 6/24/08.

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

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 110,000-person-strong Motley Fool CAPS community of stock pickers speaks with a poor rating or a negative pitch. You should listen, too.

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

Worse
We begin with Grubb & Ellis, which lost a key executive yesterday. According to the company's press announcement, "Grubb & Ellis Company ... announced today that Robert H. Osbrink, Executive Vice President and Chairman of Transaction Services, has left the Company effective immediately. [Emphasis added.]

No reason given. No lead-time. It'd be alarmist to suggest dirty dealings, so I won't. But I've never seen a sudden resignation augur excellent returns for shareholders.

Worser
Next up is R.H. Donnelley, a former guest in this column for a not-so-artful dividend dodge. On Monday, the company said it would exchange $761.9 million in old debt for $412.9 million -- which I calculate to be $419.2 million -- in new debt.

It's a great short-term deal for shareholders. Most R.H. Donnelley bondholders will receive $0.70 or less for every dollar of debt they hold.

Of course, there's a catch that makes this deal far less attractive over the long haul. R.H. Donnelley's new notes offer 11.75% in annual interest, well above the 6.875% to 8.875% it was paying. Says something about the company's credit quality, doesn't it?

Worst
But our winner is Virgin Mobile, which fired another salvo in what appears to be a margin-crushing price war among mobile-service providers.

Virgin says it will offer unlimited calls on its network for $79.99 a month, a rate that undercuts by $20 the unlimited-calling plans that Verizon (NYSE:VZ), AT&T (NYSE:T), and T-Mobile introduced in February.

Virgin and its scorched-earth mobile marketing plan ... Tuesday's worst stock in the CAPS world.

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