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

Jan. 13 Weekly Loss My Watchlist
Metabloix (Nasdaq: MBLX) $2.54 51% Add
WebMD (Nasdaq: WBMD) $27.76 27% Add
hhgregg (NYSE: HGG) $10.68 23% Add
Complete Genomics (Nasdaq: GNOM) $2.86 23% Add
Camelot Info Systems (NYSE: CIS) $2.18 22% Add

Source: Barron's.

Metabolix was the market's biggest loser, shedding a little more than half of its value after Archer Daniels Midland backed out of a joint venture for biodegradable plastics.

WebMD called in sick with several different maladies. The medical-website operator announced that its CEO is leaving the company, it was no longer considering a sale of the company, and its outlook for 2012 is looking rather weak.

Shares of hhgregg laid an egg, after the consumer-electronics retailer hosed down its near-term prospects. The chain specializing in big-ticket appliances and gadgetry now is looking to earn no more than $1.15 a share this fiscal year. Its earlier outlook was calling for profitability per share to come in between $1.26 and $1.41.

Complete Genomics was one of the market's biggest winners the prior week, but shares of the genetics specialist went the wrong way this time around after Oppenheimer & Co. downgraded the stock.

Finally we have Camelotgetting lanced a lot, as class action attorneys continue to file lawsuits against the Chinese IT services provider, alleging that Camelot made misleading financial statements before the stock began crashing last year.

It was a rough week for these five stocks. If you want to shake yesterday's losers and ride tomorrow's winners, a new special report reveals The Motley Fool's top stock for 2012. It's free, but only for a limited time, so check it out now.

Motley Fool newsletter services have recommended buying shares of hhgregg. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insightsmakes us better investors.

Longtime Fool contributor Rick Munarriz calls them as he sees them. He owns no shares in any of the stocks in this story and is also part of the Rule Breakers newsletter research team, seeking out tomorrow's ultimate growth stocks a day early. The Motley Fool has a disclosure policy.