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

July 5

Weekly Loss

Linn Energy (NASDAQ:LINE)

$23.45

29%

KiOR (NASDAQOTH:KIORQ)

$4.75

17%

InterDigital (NASDAQ:IDCC)

$38.62

14%

American Capital Agency (NASDAQ:AGNC)

$20.76

10%

BlackBerry (NASDAQ:BBRY)

$9.55

9%

Source: Barron's.

Let's start with Linn Energy. Units of the energy specialist fell after the SEC launched an inquiry into Linn's accounting, its hedging practices, and its pending acquisition of Berry Petroleum.

An inquiry isn't fatal. Linn's annualized yield of 10.9% after the past week's 29% slide will make it pretty attractive to income investors if the inquiry turns up clean. However, there's no saying how far the units will continue to tumble if there's fire behind the smoke.

KiOR slipped after the renewable-fuel company revealed that it made its first shipment of cellulosic gasoline and diesel. This is naturally welcome news, but it's easy to see the "sell on the news" adage playing itself out for the volatile stock.

InterDigital fell earlier in the week after coming up short in a patent battle. A judge overseeing InterDigital's case against several smartphone manufacturers validated the company's patents but found that the companies didn't infringe on the intellectual property. The final decision will be made in October, but it doesn't bode well for a company that can't afford to come up short in its bread-and-butter patent litigation.

American Capital Agency slipped along with most mortgage-backed REITs. With signs of an improving economy pushing mortgage rates higher, there are fears over the Federal Reserve's eventual tapering of its monthly purchases of income securities. Quantitative easing was keeping rates low, boosting the net interest margin of leveraged mortgage REITs.

Finally, we have BlackBerry continuing to fall after a horrific quarterly report a week earlier. The real shocker in the report was the shipment of a mere 2.7 million handsets running the smartphone pioneer's updated mobile operating system. This was supposed to be the platform that made BlackBerry a contender again.

Ready for a bounce
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Longtime Fool contributor Rick Munarriz and The Motley Fool have no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools don't 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.