There are always red arrows pointing down.

Stocks sink in all environments, and that includes the here and now. We're celebrating the second anniversary of the bull market rally -- a dramatic run that has seen the S&P 500 nearly double in that time -- but there are still companies that find ways to be party poopers. Crummy earnings, bad corporate decisions, and investor apathy will find some companies falling out of favor during any given week.

Let's take a closer look at five of this past week's biggest sinkers.

Company

3/4/11

Weekly Loss

My Watchlist

Central European Distribution (Nasdaq: CEDC)

$12.79

(43%)

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Amylin Pharmaceuticals (Nasdaq: AMLN)

$11.07

(29%)

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Quepasa (AMEX: QPSA)

$7.37

(27%)

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YRC Worldwide (Nasdaq: YRCW)

$2.50

(27%)

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Kendle International (Nasdaq: KNDL)

$9.07

(25%)

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Source: Barron's.

Central European Distribution broke out a set of bad news nesting dolls. The vodka giant posted a wider quarterly loss than expected earlier in the week. Credit Suisse and Nomura went on to downgrade the stock. Credit rating agency Moody's then advised investors that Central European Distribution's debt is under review for a possible downgrade.

Amylin came up empty on a comparative clinical study for its diabetes drug. All that Amylin and its Big Pharma partners needed to do was prove that its weekly injected Bydureon was as good as the daily needle pricks required by Novo Nordisk's (NYSE: NVO) Victoza. It didn't, though Bydureon didn't miss by much. It should still hit the market, and remain a compelling choice for Victoza users weary of the daily shots.

What happened, Quepasa? I took some lumps for calling the Hispanic-targeting social network overvalued last month. I don't look so dumb now that the stock has shed nearly half of its value. The website operator posted a sequential dip in monthly usage for the shorter month of February. It did report promising engagement metrics, but that only means that a sliver of its 31.7 million registered users are actually still active on the social network. The upside here is that the stock is no longer outrageously overpriced.

YRC Worldwide shifted into reverse after the trucker agreed on a restructuring proposal with its creditors and the Teamsters. The move would clean up YRC's problematic balance sheet, but shareholders are spooked by the massive dilution that it would bring about.

Kendle was only lit at the losing end after the provider of clinical services posted uninspiring quarterly results. It posted an operating loss for the period, even after backing out one-time restructuring costs and goodwill impairment charges.

It was a rough week for these five stocks. Let's see which ones bounce back this week.

Which of these five stocks do you think bottomed out last week? Share your thoughts in the comment box below.

The Fool owns shares of Kendle International. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors.

Longtime Fool contributor Rick Munarriz enjoys cheering on winners and whispering words of encouragement to the losers. He does not own shares in any of the companies in this story. He is also part of the Rule Breakers newsletter research team, seeking out tomorrow's ultimate growth stocks a day early. The Fool has a disclosure policy.