There's never a shortage of losers in the stock market.

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

Company

Oct. 26

Weekly Loss

My Watchlist

Overseas Shipholding (NYSE:OSG)

$1.23

(62%)

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Tempur-Pedic (NYSE:TPX)

$25.40

(23%)

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Crocs (NASDAQ:CROX)

$12.73

(22%)

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iRobot (NASDAQ:IRBT)

$17.99

(22%)

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Cliffs Natural Resources (NYSE:CLF)

$36.49

(18%)

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Source: Barron's.

Overseas Shipholding was the market's biggest loser, shedding nearly two-thirds of its value after revealing that it's considering strategic alternatives including the possibility of filing for bankruptcy reorganization. Naturally, Moody's and S&P downgraded the company's credit rating after that.

Tempur-Pedic was as lumpy as the mattresses it seeks to replace. The premium bedding maker posted another disappointing quarter, slashing its top- and bottom-line guidance for the entire year.

Shares of Crocs slipped after the maker of resin footwear missed Wall Street's sales targets. Weakness in once-strong overseas markets also finds Crocs hosing down its projections for the balance of the year.

iRobot is malfunctioning. The maker of home and defense robotics posted better-than-expected results for its most recent quarter. iRobot has been very good on that front. However, weak defense spending is forcing the company to forecast near-term weakness in its business.

Finally we have Cliffs Natural Resources. It isn't easy to be a miner when the commodity that you are extracting -- in this case, seaborne iron ore -- sees its average selling price fall by more than a third over the past year. The result is that Cliffs margins are getting crushed.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.