These Top Penny Stocks in 2014 Gained as Much as 129% Last Week

Investors who bought in on the top penny stocks last week brought home gains as high as 129% in just a matter of days.

Those potential windfalls are what makes penny stock investing so attractive. While there are numerous risks to investing in penny stocks, the rewards are just as abundant.

The top two penny stocks last week more than doubled shareholders' investments, and every stock on this list brought home a gain of at least 55%.

Now, here is last week's top penny stocks list...

top penny stocksTop 5 Penny Stock Gains

MagneGas Corp. (Nasdaq: MNGA) posted the biggest gain among penny stocks last week when it jumped 129% through Friday. MagneGas is an alternative energy company that produces hydrogen-based energy through the gasification of liquid waste. At one point Thursday, MNGA traded at its 52-week high of $2.37. The stock was up last week on news that MagneGas' fuel was selected for four demolition projects requiring torch cutting. The company is headquartered in Tarpon Springs, Fla., and has a market cap of just $48 million.

IsoRay Inc. (NYSEMKT: ISR) was another triple-digit winner when it posted a gain of 114% last week. IsoRay designs and develops isotope-based products that are used in the treatment of cancer and other malignant diseases. Last week, ISR announced that it had sold more than 5.6 million of its shares to two institutional investors for a price of $2.60 per share. ISR shares had opened the week at $1.09 and ended the week at $2.41.

Aastrom Biosciences Inc. (Nasdaq: ASTM) develops regenerative medicines that are used to treat damaged or diseased tissues. The company uses cell-manufacturing technologies to treat patients using their own bone marrow. Last week, ASTM shareholders were treated to an 85% gain, as the stock climbed $2.98. ASTM is on the expensive side for a penny stock, as it currently trades at $5.13. Aastrom has a market cap of just $22 million.

ASTM will be making a presentation at the 2014 Regen Med Investor Day on March 26. The specific topic of Aastrom's presentation is still unknown, and any announced breakthroughs for ASTM products or therapies could serve as a catalyst for the stock.

Pernix Therapeutics Holdings Inc. (Nasdaq: PTX) is a pharmaceutical company known best for developing multiple treatments for cough and cold, including BROVEX, ALDEX, and PEDIATEX. Shares of PTX were up almost 70% last week and closed out the week near its 52-week high of $6.02. PTX stock had started the week at $3.90. Pernix is currently developing a non-codeine cough suppressant called theobromine and has a market cap of almost $213 million.

Mechanical Technology Inc. (OTC: MKTY) rounds out the list of best penny stocks this week, having gained nearly 55% in the past five days. MKTY develops micro fuel cells and non-contact precision instruments. Last week, the company announced a new sales agreement in which it would be providing its new permanent magnet motors to oil and gas company Weatherford International Ltd. That news was one of the driving forces behind MKTY's $0.60 gain last week.

Do you invest in penny stocks? Which penny stock will be the next triple-digit winner? Share your thoughts on Twitter @moneymorning using #PennyStocks.

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