There are always red arrows pointing down.

The losers are even easier to stop on crummy weeks, and that's just what we had last week with the Dow, S&P 500, and Nasdaq tumbling 1.5%, 1.9%, and 2.7%, respectively.

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

Company

March 18

Weekly Loss

My Watchlist

TBS International (Nasdaq: TBSI)

$2.00

(40%)

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Online Resources (Nasdaq: ORCC)

$3.88

(39%)

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KV Pharmaceutical (NYSE: KV-A)

$8.50

(29%)

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Sanmina-SCI (Nasdaq: SANM)

$10.50

(26%)

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Uranerz Energy (AMEX: URZ)

$3.10

(22%)

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Source: Barron's.

TBS tanked after the Dublin-based dry cargo shipper posted disappointing quarterly results, warning that it may be in default by the end of June.

Janney and Oppenheimer analysts downgraded shares of Online Resources after the payment platform provider abandoned plans to smoke out strategic alternatives. Online Resources had rallied earlier this year after receiving an unsolicited buyout offer in January.

KV Pharmaceutical has been the poster child for volatility in recent weeks. It's been a regular among the weekly winners and losers. It fell this week after a pair of senators urged the Federal Trade Commission to investigate the drugmaker's pricing practices. KV is boosting the price of its Makena injection to prevent premature births from $10 to $1,500.

Sanmina-SCI dealt investors a one-two punch. The provider of outsourcing manufacturing services revised its fiscal second-quarter guidance lower. It also announced that its COO would be stepping down.

Finally, we have Uranerz Energy. The uranium supplier took a hit given the fallout of the nuclear reactor tragedy in Japan. Uranerz fell alongside Denison Mines (AMEX: DNN), Ur-Energy (AMEX: URG), and other uranium miners. Uranerz shares began to bounce back by the end of the week, suggesting that nuclear power remains an inevitable energy source in the near term.

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.

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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.