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.


Oct. 7 Weekly Loss My Watchlist
Clearwire (Nasdaq: CLWR) $1.39 (40%) Add
Gentiva Health Services (Nasdaq: GTIV) $3.59 (35%) Add
Illumina (Nasdaq: ILMN) $27.18 (34%) Add
Cardiovascular Systems (Nasdaq: CSII) $7.58 (34%) Add
Sify (Nasdaq: SIFY) $2.87 (28%) Add

Source: Barron's.

Shares of Clearwire got creamed after partner -- and occasional lone cheerleader -- Sprint Nextel (NYSE: S) revealed that it may be ready to switch from Clearwire's WiMAX to the more popular LTE 4G standard. Then again, it's not as if Sprint got off easy. The wireless carrier's stock fell 21% on the week.

Gentiva called in sick after a few analysts downgraded the stock. A Senate panel is alleging that Gentiva and some of its rivals are providing -- and naturally billing for -- medically unnecessary patient care.

Illumina turned DNA into DOA after the genetic-analysis instrument maker lowered its revenue target for the current quarter and suspended its full-year guidance. Then again, investors may have seen this coming after fellow genetics gear maker Pacific Biosciences of California (Nasdaq: PACB) announced chunky layoffs last month.

Cardiovascular skipped a beat after the medical device manufacturer posted preliminary results that were below its earlier guidance. The company will update its outlook for all of fiscal 2012 when it reports its quarterly results next month.

Finally, Indian Web services provider Sify slipped on no material news. Monday was a particularly big day for the selling of Internet bellwethers in the world's second-most-populous nation, but Sify failed to bounce back as its stock fell during all but one of last week's trading days.

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

Motley Fool newsletter services have recommended buying shares of Illumina and Pacific Biosciences of California. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.

Longtime Fool contributor Rick Munarriz calls them as he sees them. He does not own shares in any of the stocks in this story. Rick is also part of the Rule Breakers newsletter research team, seeking out tomorrow's ultimate growth stocks a day early.