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

Nov. 2

Weekly Loss

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Active Network (NASDAQ:ACTV)

$5.42

(40%)

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Western Union (NYSE:WU)

$11.95

(33%)

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Vringo (NYSEMKT: VRNG)

$2.77

(31%)

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Glu Mobile (NASDAQ:GLUU)

$2.56

(21%)

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VIVUS (NASDAQ:VVUS)

$14.33

(18%)

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Source: Barron's.

The Big Board's biggest sinker last week was Active Network. The leading provider of online registrations for marathons, triathlons, and other organized events was running the wrong way after a poorly received quarterly report.

Active Network's eyeing a larger-than-expected sequential dip in revenue for the fourth quarter, and targeting another net loss on top-line growth of 12% to 14% in 2013 was shy of what the market was expecting.

Western Union bounced like a bad check after the money-transfer giant offered up unimpressive guidance. Western Union is lowering prices in key markets in a move to combat competitive pressures, and that obviously won't help results in the near term.

Vringo stumbled after a judge moved to narrow the window of prior damages that the company can go after in its patent infringement suit against several dot-com bellwethers.

Several analysts moved to downgrade Glu Mobile on Friday after the app maker posted troublesome guidance. It sees a widening deficit for the period, expecting revenue to come in as much as 27% below Wall Street's top-line target.

VIVUS shed some weight after health-care research firm IMS Health reported that physicians have been writing far fewer prescriptions for VIVUS' anti-obesity drug, Qsymia, than Wall Street was expecting this quarter.