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

Aug. 3 Weekly Loss My Watchlist
Halozyme Therapeutics (Nasdaq: HALO) $4.61 (53%) Add
Zipcar (Nasdaq: ZIP) $6.75 (39%) Add
Molycorp (NYSE: MCP) $11.49 (34%) Add
Dendreon (Nasdaq: DNDN) $4.45 (29%) Add
RealD (NYSE: RLD) $9.87 (23%) Add

Source: Barron's.

Halozyme Therapeutics was clobbered after the FDA rejected its drugs.

Zipcar went in reverse after the car-sharing service posted brutal quarterly results that missed Wall Street's top- and bottom-line targets. The leading provider of auto rentals by the hour also presented soft guidance for the current quarter.

Molycorp took a hit after stunning the market with a steep and unexpected quarterly loss. Sluggish prices for the company's rare-earth minerals are holding Molycorp back.

Cancer-drug developer Dendreon tumbled after posting a wide loss and announcing a cost-cutting plan that includes closing down one of its manufacturing facilities.

RealD screened a horror movie after posting a quarterly profit that clocked in at just a third of what analysts were expecting. Increasing costs and an unflattering mix of recycled 3-D eyewear in shipments slammed margins.

Ready for a bounce
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