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. 10 Weekly Loss My Watchlist
Ubiquiti Networks (Nasdaq: UBNT) $8.71 (30%) Add
Roundy's (Nasdaq: RNDY) $7.71 (21%) Add
Exelixis (Nasdaq: EXEL) $4.46 (20%) Add
Achillion Pharmaceuticals (Nasdaq: ACHN) $5.61 (17%) Add
priceline.com (Nasdaq: PCLN) $563.16 (15%) Add

Source: Barron's.

Ubiquiti Networks tumbled after the company issued guidance calling for a shocking sequential decline in revenue and profitability. Terminated distributors have apparently created a model-stinging market of counterfeit versions of Ubiquiti's AirMax product.

Grocery stores have had it rough this earnings season, and the recently public Roundy's is no different. Shares of the supermarket chain tumbled after the company posted disappointing quarterly results. The silver lining here is that Roundy's is committed to maintaining its meaty dividend rate, resulting in a yield that got even fatter after the stock's drop.

Exelixis took a hit after issuing secondary stock and convertible debt offerings. Investors don't like to see their stakes in the drugmaker diluted that way, even if it means that Exelixis is raising money.

Achillion Pharmaceuticals put out encouraging news for its hepatitis C treatment, but a disappointing quarter and concerns about the treatment itself held the stock back.

Even though Priceline managed to once again beat Wall Street's profit target, investors were unimpressed by the online travel portal's uninspiring guidance. Weakness in Europe -- a strong market for the company's Booking.com website -- is weighing on its growth potential.

Ready for a bounce
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