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. 26 Weekly Loss My Watchlist
Star Scientific (Nasdaq: CIGX) $1.81 (38%) Add
Pacific Sunwear (Nasdaq: PSUN) $1.41 (32%) Add
OmniVision Technologies (Nasdaq: OVTI) $17.27 (28%) Add
Camelot Information Systems (NYSE: CIS) $4.50 (21%) Add
Motricity (Nasdaq: MOTR) $1.99 (19%) Add

Source: Barron's.

Star Scientific's emphasis on smokeless cigarette alternatives may be a sound strategy, but it was the butt of Wall Street's joke after losing a patent infringement battle against Reynolds American (NYSE: RAI). The court upheld some of Star's patents, but didn't feel compelled to revisit a 2009 infringement case where Star came up short.

Teen apparel retailer Pacific Sunwear washed ashore after providing a gloomy outlook for its back-to-school quarter. PacSun sees negative same-store sales and a much larger loss than the pros were expecting for the current quarter.

OmniVision had investors rubbing their eyes after the image sensor giant warned of a soft quarter. OmniVision's been a winner in the past as a popular choice in powering smartphone cameras for handset makers, but some are now wondering what OmniVision's role will be with Apple (Nasdaq: AAPL) on the upcoming iPhone 5.

Camelot Information Systems continues to lose ground after an uninspiring quarterly report posted a week earlier. The Chinese provider of IT and enterprise application services had seen its revenue and adjusted earnings climb 35% and 22%, respectively. Investors don't like to see the top line growing faster than the bottom line.

Then there's Motricity. The mobile phone software provider cut its CEO loose without an immediate replacement. Normally, investors cheer a change at the top after a brutal performance, but the sense of being rudderless isn't always pretty.

It was a rough week for these five stocks; let's see if they bounce back.