The Week's Top Stock Gainers

Sandwiched smack between the Christmas and New Year holidays, the past week was largely a sleeper. Volume for the Dow Jones Industrial Average (INDEX: ^DJI) was close to half of its 2011 average during the week as investors and traders took time away from the market's grind. News was light, but there was enough pessimism to keep the U.S. markets in the red for the last week of the year.

The Dow slid 0.6% for the week, while the broader Russell 3000 dropped 0.7%. Investors worked on a defensive posture in the final days of 2011, and equity-market safe haven sectors were the top performers.

Top 3 performing sectors

Source: S&P Capital IQ. Weekly price change is Dec. 23-Dec. 30. Monthly price change is Nov. 30-Dec. 30.

Representing the lagging tech sector was MoSys (NAS: MOSY) , an intellectual-property developer that focuses on memory technology. The company's stock skyrocketed 41% in the final day of 2011 trading after it announced that it's selling 73 patents to Tessera Technologies (NAS: TSRA) subsidiary Invensas for $35 million. The amount that MoSys was able to get for the patents surprised some analysts, and it will give the company funding it needs to continue development of its new products.

Also catching a serious tailwind during the week was oil and gas exploration company Endeavour International (NYS: END) . Endeavour's shares soared after the company announced that it's buying three oil fields from ConocoPhillips (NYS: COP) for $330 million. The good times continued on Wednesday as shares shot up again after Rodman & Renshaw upgraded the stock to outperform.

Top 3 performing Russell 3000 companies

Source: S&P Capital IQ. Weekly price change is Dec. 23-Dec. 30.

Also among the week's top performers were Diamond Foods (NAS: DMND) and Hyperdynamics (NYS: HDY) . Just a few weeks ago, Hyperdynamics was posting up with the market's biggest losers as investors fretted over a drilling stoppage. This week, the stock was flying high with the gainers after the company announced that it had resumed drilling in the Republic of Guinea. The stock was up 13% for the week.

Diamond Foods, meanwhile, jumped nearly 14% after rumors swirled that investing icon David Einhorn had taken a stake in the company. The market has swatted around Diamond's stock ever since the company announced that it's investigating its accounting -- in particular, its payments to walnut growers. When a top investor like Einhorn jumps in on a beaten-down stock, the move tends to be followed by plenty of copycat investors. Blind copy-catting like that isn't a very Foolish way to invest, but if the Einhorn rumors are confirmed, there could be more upside for the stock.

That's it for this week's top-performers recap. If you're looking for some ideas for strong outperformers in the year ahead, The Motley Fool has created a brand new free report titled "The Motley Fool's Top Stock for 2012." In it, my fellow Fools reveal a top pick that's poised for explosive growth ahead. Get instant access -- it's free.

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